EXHIBIT 10.5(K)

                        TEXAS ASSOCIATION OF REALTORS(R)
               COMMERCIAL IMPROVED PROPERTY EARNEST MONEY CONTRACT

         THIS FORM IS FURNISHED BY THE TEXAS ASSOCIATION OF REALTORS(R)
     FOR USE BY ITS MEMBERS. USE OF THIS FORM BY PERSONS WHO ARE NOT MEMBERS
           OF THE TEXAS ASSOCIATION OF REALTORS(R) IS NOT AUTHORIZED.
                 (C)Texas Association of REALTORS(R), Inc., 1995


1.       PARTIES: MR. STANLEY JOBE (Seller) agrees to sell and convey to QUALITY
         AIR INC. AND/OR ASSIGNS (Buyer) and Buyer agrees to buy from Seller the
         property described below.

2.       PROPERTY:  The  real  property  situated  in  EL  PASO  County,  Texas,
         described as follows or as described on attached exhibit:

                  Lots 3 to 20, 41 to 58 Block 15 Westway Unit #2
                  809 Kingsway

         together  with  (a)  all  buildings,  improvements,  fixtures,  and all
         property of every kind and character and description (personal or real)
         owned by Seller located on, attached to, or used in connection with the
         Property;  (b) all  rights,  privileges  and  appurtenances  pertaining
         thereto,  including any right,  title, and interest of Seller in and to
         adjacent streets,  alleys, and rights-of-way;  (c) Seller's interest in
         and to all leases or rents and security deposits; (d) Seller's interest
         in and to all licenses and permits  with respect to the  Property;  (e)
         Seller's  interest  in all third party  warranties  or  guaranties,  if
         transferable,  relating  to the  Property or to any  tangible  personal
         property and fixtures  located on,  attached to, or used in  connection
         with the  Property;  and (f) Seller's  interest in any trade names,  if
         transferable,  used in connection with the Property.  The property sold
         by this  contract  is called  the  "Property".  The  metes  and  bounds
         description  determined by the survey of the Property  under  paragraph
         6(b) shall replace any exhibit  describing the perimeter  boundaries of
         the Property if it differs from the exhibit. NOTICE: ANY PROPERTY TO BE
         EXCLUDED FROM THE SALE SHOULD BE DESCRIBED IN PARAGRAPH 11.

3.       SALES PRICE:
<TABLE>
<CAPTION>

<S>      <C>      <C>                                                                  <C>
         (a)      Cash portion of Sales Price payable by Buyer. . . . . . . . . . . .  $ 450,000.00
                                                                                       ------------
         (b)      Sum of all financing described in paragraph 4. . . . . . . . . . . . $   -0-
                                                                                       ------------
         (c)      Sales price [sum of (a) and (b)]. . . . . . . . . . . . . . . . . . .$ 450,000.00
                                                                                       ------------
</TABLE>

5.       EARNEST  MONEY:  Buyer shall  deposit $ 10,000.00 as Earnest Money with
         SIERRA  TITLE  (Escrow  Agent) at 1014 N. MESA,  EL PASO,  TEXAS  79902
         (Address) on the  Effective  Date of this  contract.  The Earnest Money
         shall be deposited in an |X| interest |_| non-interest  bearing account
         in a federally insured financial institution chosen by Escrow Agent and
         any interest shall be credited to Buyer.  If Buyer fails to deposit the
         Earnest Money as required by this contract, Buyer shall be in default.

6.       TITLE POLICY AND SURVEY:

|X|     (a)       TITLE POLICY:  Buyer shall furnish to Buyer at Buyer's expense
                  an Owner Policy of Title  Insurance  (the Title Policy) issued
                  by SIERRA TITLE (the Title Company) in the amount of the Sales
                  Price, dated at or after closing,  insuring Buyer against loss
                  under the  provisions  of the Title  Policy,  subject  only to
                  those title exceptions  permitted by this contract,  or as may
                  be  approved  by Buyer in writing,  and the  standard  printed
                  exceptions  contained in the promulgated form of Title Policy;
                  provided  however  that  (1)  the  exception  as to  area  and
                  boundaries  o shall  o shall  not be  deleted  except  for any
                  shortages  in area at the  expense of |X| Buyer o Seller;  and
                  (2)  the  exception  as  to  restrictive  covenants  shall  be
                  endorsed "None of Record", unless restrictions are approved by
                  Buyer.  Within 15 days after the Title Company receives a copy
                  of this contract  Seller shall furnish Buyer a commitment  for
                  Title Insurance (the Commitment) including copies of recorded


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Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------

                  documents  evidencing title exceptions.  Seller authorizes the
                  Title Company to deliver the Commitment and related  documents
                  to Buyer at Buyer's  address.  Buyer  shall have 30 days after
                  receipt of the  Commitment  and  legible  copies of  documents
                  evidencing  title  exceptions  required  by this  contract  to
                  object in writing to matters disclosed in the Commitment other
                  than the standard  printed  exceptions as described or limited
                  in this paragraph.

[ ]      (b)      SURVEY REQUIRED:  (Check (1) or (2) only)

         [ ]      (1)      Within ---------- days after: o the Effective Date of
                           this contract; Rx the date by which Buyer is required
                           to complete  inspections,  studies or  assessments in
                           paragraph 7(b); (check (i) or (ii) only):

                  |X|      (i) Buyer  may  obtain a survey  of the  Property  at
                           Buyer's expense.

7.       PROPERTY CONDITION/FEASIBILITY STUDIES: (Check (a) or (b) only)

|X|      (a)      PRESENT CONDITION:

         |X|      (1)      Buyer  accepts the  Property  in its present  "as-is"
                           condition.  Buyer shall pay for any repairs  required
                           by a lender.

         [ ]      (2)      Buyer  accepts the Property in its present  condition
                           provided  that  Seller,  at Seller's  expense,  shall
                           complete the following repairs prior to closing:-----
                           -----------------------------------------------------
                           ----------------------- Buyer shall pay for any other
                           repairs required by a lender.

|X|      (b)      INSPECTIONS AND FEASIBILITY STUDIES:  Within 60 days after the
                  Effective Date of this contract Buyer, at Buyer's expense, may
                  complete or cause to be completed  inspections of the Property
                  (including  all  improvements  and fixtures) by inspections of
                  Buyer's  choice.  Inspections  may include but are not limited
                  to:  (i)  physical  property  inspections  including,  but not
                  limited to, structural pest control,  mechanical,  structural,
                  electrical, or plumbing inspections; (ii) economic feasibility
                  studies;  (iii)  any  type  of  environmental   assessment  or
                  engineering  study  including the performance of tests such as
                  soils  tests,  air  sampling,  or  paint  sampling;  and  (iv)
                  compliance  inspections  to determine  compliance  with zoning
                  ordinances,  restrictions, building codes, and statutes (e.g.,
                  ADA, OSHA, and others).  Seller shall permit Buyer and Buyer's
                  inspectors access to the Property at reasonable times.  Seller
                  shall pay for turning  utilities on for inspections.  If Buyer
                  determines, in Buyer's sole judgment, that the Property is not
                  suitable for any reason for Buyer's  intended use or is not in
                  satisfactory condition, then Buyer may terminate this contract
                  by providing  written notice of termination  and copies of all
                  reports of inspections,  studies, or assessments  completed or
                  caused to be completed by Buyer under this paragraph to Seller
                  within the time required to complete the inspections, studies,
                  or  assessments  under this  paragraph,  and the Earnest Money
                  shall  be  refunded  to  Buyer  less  the  sum  of $ -0- to be
                  retained by Seller as  independent  consideration  for Buyer's
                  right to  terminate  under this  paragraph.  If Buyer does not
                  terminate this contract within the time required by objections
                  with respect to the inspections, studies and assessments under
                  this  paragraph  shall be  deemed  waived  by  Buyer.  If this
                  contract  does not close  through  no fault of  Seller,  Buyer
                  shall  restore  the  Property  to its  original  condition  if
                  altered due to inspections,  studies, or assessments completed
                  by Buyer or  Buyer's  inspectors.  Within  80 days  after  the
                  Effective Date of this contract  Seller shall deliver to Buyer
                  (strike any not to be delivered):

                           (1)      a current rent roll of all leases  affecting
                                    the Property  certified by Seller to be true
                                    and correct;


                                       -2-

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Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------

                           (3)      a current inventory of all tangible personal
                                    property  and  fixtures,  if any,  owned  by
                                    Seller and located on,  attached to, or used
                                    in connection with the Property;

                           (4)      copies  of all  notes  and  deeds  of  trust
                                    assumed or taken subject to by Buyer;

                           (6)      copies of all warranties and guaranties,  if
                                    any,  relating to the Property,  or any part
                                    thereof, or to be tangible personal property
                                    and fixtures owned by Seller and located on,
                                    attached to, or used in connection  with the
                                    Property;

                           (7)      copies of all fire, hazard,  liability,  and
                                    other  insurance  policies held by Seller on
                                    or affecting the Property;

                           (9)      a  copy   of  the   "as-built"   plans   and
                                    specifications of the Property,  in Seller's
                                    possession, if any;

                           (12)     copies   of   all   previous   environmental
                                    assessments,  studies, or analyses affecting
                                    the Property in Seller's possession.

8.       BROKER'S  REPRESENTATION  AND FEES: John T. Hellard (Listing Broker): o
         represents Seller only; |X| acts as an intermediary  between Seller and
         Buyer.  Any  other  broker  represents:  o Seller as  Listing  Broker's
         Subagent;  o Buyer only.  Seller shall pay Listing  Broker (choose only
         one):

[ ]      (a)      the fee specified by separate agreement between Listing Broker
                  and Seller.

|X|      (b)      a total cash fee of either  $------- or 5 % of the total Sales
                  Price in -------------------- County, Texas on closing of this
                  sale,  which Escrow agent shall pay from Seller's  proceeds of
                  the sale.  If Seller  defaults,  the cash fee shall be due and
                  payable in full. If Buyer defaults, Escrow Agent is authorized
                  to pay Listing  Broker  one-half of any Earnest  Money  Seller
                  receives  under this  contract not to exceed the amount of the
                  cash fee.

9.       CLOSING:

         (a)      The  closing of the sale shall be on or before  April 28, 1997
                  or within 7 days after the  objections  to title or the survey
                  have been cured,  whichever  date is later (the Closing Date);
                  however, if financing or assumption approval has been obtained
                  pursuant to paragraph 4, the Closing Date shall be extended up
                  to 15 days only if necessary to comply with  lender's  closing
                  instructions (for example,  survey, insurance policy, property
                  repairs,  closing  documents).  If either party fails to close
                  this sale by the Closing Date, the non-defaulting  party shall
                  be entitled to exercise  the  remedies  contained in paragraph
                  15.

         (b)      At closing Seller shall furnish,  at Seller's  expense (strike
                  any not to be furnished):

                  (1)      tax  statements  showing no  delinquent  taxes on the
                           Property;

                  (2)      a |X|  General [ ] Special  Warranty  Deed  conveying
                           good and  indefeasible  title to the Property showing
                           no  additional   exceptions  to  those  permitted  in
                           paragraph 6;

                  (3)      If  applicable,  a Bill of Sale  with  warranties  to
                           title conveying  title,  free and clear of all liens,
                           to any  personal  property  defined  as  part  of the
                           Property  in   paragraph  2  and   conveyed  by  this
                           contract;

                  (8)      evidence that the person  executing  this contract is
                           legally capable and authorized to bind Seller.


                                       -3-

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Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------


10.      POSSESSION: Seller shall deliver possession of the Property to Buyer on
         -------------- in its present or required repaired condition,  ordinary
         wear and tear  excepted.  Any  possession  by Buyer prior to closing or
         Seller after closing that is not authorized by a separate written lease
         agreement,   shall   establish   a  landlord-   tenant  at   sufferance
         relationship between the parties.

11.      SPECIAL PROVISIONS:

         1 -      Buyer  to pay for all  closing  cost and  Seller  to pay his
                  legal fees.

         2 -      Buyer Accepts property in its present condition.  See Addendum
         3 -      Buyer to pay for own environmental study.
         4 -      Seller agrees to lease to Buyer subject property for 90 days
                  or less at $5,000.00 per month beginning February 1st, 1997.
                  See attached lease agreement.

12.      SALES EXPENSES:  To be paid in cash at or prior to closing:

         (a)      Seller's  Expenses:  Releases  of  existing  liens,  including
                  prepayment  penalties and recording fees;  release of Seller's
                  loan liability; tax statements or certificates; preparation of
                  deed;  one-half of escrow fee; and other expenses  stipulation
                  to be paid by Seller under other provisions of this contract.

         (b)      Buyer's  Expenses:  All loan fees or expenses (e.g.,  fees for
                  application,origination,   discount,  appraisal,   assumption,
                  recording,  tax  service,  mortgagee  title  policies,  credit
                  reports,  document preparation and the like);  preparation and
                  recording  of deed of trust  to  secure  assumption;  required
                  premiums  for  flood and  hazard  insurance;  interest  on all
                  periodic  installment payment notes from date of disbursements
                  to  one  payment  period  prior  to  dates  of  first  monthly
                  payments; one-half of escrow fee; fees for copies and delivery
                  of title commitment and related documents;  and other expenses
                  stipulated to be paid by Buyer under other  provisions of this
                  contract.

         (c)      If any  sales  expense  exceeds  the  amount  stated  in  this
                  contract  to  be  paid  by  either  party,  either  party  may
                  terminate this contract unless either party agrees to pay such
                  excess.

13.      PRORATIONS AND ESTOPPEL CERTIFICATES:

         (a)      PRORATIONS:  Insurance  (at  Buyer's  option) if a transfer is
                  permitted by the  insurance  carrier,  interest on any assumed
                  loan,  current taxes,  and any rents shall be prorated through
                  the Closing  Date.  If the amount of the ad valorem  taxes for
                  the year in which the sale is closed is not  available  on the
                  Closing Date, proration of taxes shall be made on the basis of
                  taxes  assessed in the previous year,  with a subsequent  cash
                  adjustment  of such  proration to be made  between  Seller and
                  Buyer, if necessary, when actual tax figures are available. If
                  Buyer is assuming payment of or taking subject to any existing
                  loan on the Property,  all reserve deposits for the payment of
                  taxes,   insurance   premiums,   and  other  charges,shall  be
                  transferred  to Buyer by Seller and Buyer  shall pay to Seller
                  the amount of such reserved deposits at closing.

         (b)      ESTOPPEL  CERTIFICATES:  Within N/A days  after the  Effective
                  Date of this Contract,  Seller shall deliver to Buyer estoppel
                  certificates  signed  not  earlier  than  N/A by  each  tenant
                  leasing  space in the Property  stating  that,  as of the date
                  signed:  no  default  exists  under  the  terms  of the  lease
                  agreement by either lessor or lessee; the amount of any rental
                  payments  made in advance,  if any; the amount of any security
                  deposits made, if any; the amount of any offsets against rent,
                  if any;  and that  the  tenant  has no  defenses  against  the
                  payment  of  rent  accruing  under  the  terms  of  the  lease
                  agreement.  If  Seller  is  unable  to  deliver  the  estoppel
                  certificates  in accordance  with the terms of this  paragraph
                  without fault by the specified time,  Buyer may: (i) terminate
                  this  contract  and the  Earnest  Money  shall be  refunded to
                  Buyer; (ii) extend the time for performance up to 15

                                       -4-

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Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------
                  days and the Closing Date shall be extended as  necessary;  or
                  (iii)  waive  Seller's  requirement  to deliver  the  estoppel
                  certificates.

         (c)      Seller  shall,  at  closing,  tender  to  Buyer  any  security
                  deposits,  prepaid expenses, and advanced rental payments paid
                  by any and all tenants.

14.      CASUALTY LOSS AND CONDEMNATION:

         (a)      If any part of the Property is damaged or destroyed by fire or
                  other casualty loss,  Seller shall restore the Property to its
                  previous condition as soon as reasonably possible,  but in any
                  event by the  Closing  Date.  If  Seller  is  unable  to do so
                  without fault,  Buyer may: (i) terminate this contract and the
                  Earnest Money shall be refunded to Buyer; (ii) extend the time
                  for  performance  up to 15 days and the Closing  Date shall be
                  extended as  necessary;  or (iii)  accept the  Property in its
                  damaged  condition  and  accept  an  assignment  of  insurance
                  proceeds.  Provisions  of  the  Texas  property  Code  to  the
                  contrary shall not apply.

         (b)      If prior to closing  condemnation  proceedings  are  commenced
                  against any portion of the Property,  Buyer may: (i) terminate
                  this contract by written notice to Seller within 15 days after
                  Buyer  is  advised  of the  condemnation  proceeding  and  the
                  Earnest  Money shall be refunded to Buyer;  or (ii) appear and
                  defend  in  the  condemnation  proceeding  and  any  award  in
                  condemnation  shall, at Buyer's election,  become the property
                  of Seller  and the sales  price  shall be  reduced by the same
                  amount or any award shall become the property of Buyer and the
                  Sales price shall not be reduced.

15.      DEFAULT: If Buyer fails to comply with this contract, Buyer shall be in
         default.  Seller may either,  enforce specific performance,  seek other
         relief as may be provided by law, or both;  or terminate  this contract
         and receive the Earnest Money as liquidated damages,  thereby releasing
         the parties from this  contract.  If Seller is unable  without fault to
         make any noncasualty  repairs,  deliver the estoppel  certificates,  or
         deliver  the  Commitment  within  the time  allowed,  Buyer may  either
         terminate  this  contract  and receive  the  Earnest  Money as the sole
         remedy or extend the time for performance up to 15 days and the Closing
         Date shall be extended  as  necessary.  If Seller  fails to comply with
         this  contract  for any other  reason,  Seller  shall be in default and
         Buyer may either enforce specific  performance,  seek such other relief
         as may be provided by law, or both;  or  terminate  this  contract  and
         receive the Earnest  Money,  thereby  releasing  the parties  from this
         contract.

16.      ATTORNEY  FEES: If Buyer,  Seller,  Listing  Broker,  Other Broker,  or
         Escrow  Agent is a  prevailing  party in any legal  proceeding  brought
         under or with relation to this contract or this transaction, such party
         shall be entitled to recover from the non-prevailing  parties all costs
         of such proceeding and reasonable attorney fees. The provisions of this
         paragraph shall survive closing.

17.      ESCROW:  If either  party  makes  demand for the payment of the Earnest
         Money,  Escrow  Agent has the right to  require  from all  parties  and
         brokers a written release of liability of Escrow Agent for disbursement
         of the Earnest Money. Any refund or disbursement of Earnest Money under
         this  contract  shall be  reduced  by the  amount  of  unpaid  expenses
         incurred on behalf of the party receiving the Earnest Money, and Escrow
         agent shall pay the same to the creditors entitled thereto. At closing,
         the Earnest Money shall be applied first to any cash down payment, then
         to Buyer's closing costs and any excess refunded to Buyer.  Demands and
         notices required by this paragraph shall be in writing and delivered by
         hand delivery or by certified mail, return receipt requested.

18.      MATERIAL FACTS:

         (a)      Seller  shall  convey the  Property  on  closing:  (i) with no
                  liens, assessments,. Uniform Commercial Code or other security
                  interests against the Property which will not be satisfied out
                  of the  Sales  Price  unless  securing  payment  of any  loans
                  assumed by Buyer,  (ii) without any assumed  loans in default;
                  and (iii) with no parties in  possession of any portion of the
                  Property as lessees,  tenants at  sufferance,  or  trespassers
                  except  tenants  under the written  leases  delivered to Buyer
                  pursuant to his contract.

         (b)      To the best of Seller's  knowledge  and belief  (choose (1) or
                  (2) only):

                                      -5-
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Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------

                  [ ]      (1)      Seller is not aware of any material  defects
                                    to the  Property  except  as  stated  in the
                                    attached property Condition Statement.

                  |X|      (2)      Seller is not aware of:

                                    (i)      any   material   defects   to   the
                                             Property except:  ROOF SEE ADDENDUM
                                             SUITABILITY, STRUCTURE SEE ADDENDUM
                                             -----------------------------------

                                    (ii)     any   environmental    hazards   or
                                             conditions  affecting  the property
                                             which would  violate  any  federal,
                                             state    or     local     statutes,
                                             regulations,   ordinance  or  other
                                             requirements and more specifically,
                                             but without limitation, whether (1)
                                             the  Property  is or has ever  been
                                             used for  storage  or  disposal  or
                                             hazardous  substances  or materials
                                             or  toxic  waste,  a dump  site  or
                                             landfill,  or  the  housing  of any
                                             underground  tanks  or  drums;  (2)
                                             radon,   asbestos   insulation   or
                                             fireproofing, ureaformaldehyde foam
                                             insulation,   lead-based  paint  or
                                             other pollutants or contaminants of
                                             any  nature  now exist or have ever
                                             existed   on  the   Property;   (3)
                                             wetlands,  as defined by federal or
                                             state law or regulation  are on the
                                             Property;  and  (4)  threatened  or
                                             endangered    species    or   their
                                             habitat,  as  defined  by the Texas
                                             Parks and  Wildlife  Department  or
                                             the U.S. Fish and Wildlife Service,
                                             are  on  the  property;  except  as
                                             follows----------------------------
                                             -----------------------------------

19.      NOTICES:   All  notices  shall  be  in  writing  and   effective   when
         hand-delivered,  mailed by certified mail return receipt requested,  or
         sent by facsimile transmission to:

         Buyer at P.O. Box 3048             Seller at  One McKelligan Canyon Rd.
         --------------------------         ------------------------------------
                  Sunland Park, NM                     El Paso, Tx. 79930
         --------------------------         ------------------------------------
         Phone  (505) 589-5431              Phone (   )
         --------------------------         ------------------------------------
         Fax     (   )                      Fax  (   )
         --------------------------         ------------------------------------

20.      FEDERAL TAX REQUIREMENT: If Seller is a "foreign person", as defined by
         applicable  law, or if Seller fails to deliver an affidavit that Seller
         is not a "foreign  person",  then Buyer shall  withhold  from the sales
         proceeds at closing an amount  sufficient to comply with applicable tax
         law and deliver the same to the Internal Revenue Service, together with
         appropriate tax forms.  Internal  Revenue Service  regulations  require
         filing  written  reports  if cash in excess  of  specified  amounts  is
         received in the transaction.

21.      DISPUTE RESOLUTION:  The parties agree to negotiate in good faith in an
         effort to resolve any dispute  related to this contract that may arise.
         If the dispute cannot be resolved by negotiation,  the dispute shall be
         submitted  to mediation  before the parties  resort to  arbitration  or
         litigation  and a mutually  acceptable  mediator shall be chosen by the
         parties to the dispute who shall share the cost of  mediation  services
         equally.

22.      AGREEMENT  OF THE  PARTIES:  This  contract  shall  be  binding  on the
         parties,  their  heirs,  executors,  representatives,  successors,  and
         assigns.  This contract shall be construed under and in accordance with
         laws of the State of Texas. This contract contains the entire agreement
         of the parties and cannot be changed  except by written  agreement.  If
         this contract is executed in a number of identical  counterparts,  each
         counterpart  is  deemed  an  original  and  all   counterparts   shall,
         collectively,  constitute one  agreement.  Buyer o may o may not assign
         this  contract.  If Buyer assigns this contract Buyer shall be relieved
         of any  future  liability  under  this  contract  only if the  assignee
         assumes in writing all  obligations  and  liability of Buyer under this
         contract.   Addenda   which  are  part  of  this   contract   are:  SEE
         ADDENDUM---------------------------------------------------------------

                                      -6-
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Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------

23.      TIME: Time is of the essence in this contract.  Strict  compliance with
         the times for performance stated in this contract is required.

24.      EFFECTIVE  DATE: The Effective Date of this contract for the purpose of
         performance  of all  obligations  shall be the date  this  contract  is
         receipted  by the Escrow  Agent after all parties  have  executed  this
         contract.

25.      MISCELLANEOUS:

         (a)      Buyer should have an Abstract  covering the Property  examined
                  by an  attorney  of  Buyer's  selection,  or Buyer  should  be
                  furnished with or obtain a Title Policy.

         (b)      If the  Property is  situated in utility or other  statutorily
                  created district providing water,  sewer,  drainage,  or flood
                  control facilities and services, Chapter 50 of the Texas Water
                  Code  requires  Seller  to  deliver  and the Buyer to sign the
                  statutory   notice   relating   to  the   tax   rate,   bonded
                  indebtedness,  or standby fee of the  district  prior to final
                  execution of this contract.

         (c)      If the Property  adjoins or shares a common  boundary with the
                  tidally  influenced  submerged  lands  of the  state,  Section
                  33.135 of the Texas Natural Resources Code,  requires a notice
                  regarding   coastal  area  property  to  be  included  in  the
                  contract.

         (d)      Buyer should not rely upon any oral representations  about the
                  Property  from  any  source.  Seller  and any  broker  have no
                  knowledge of any defects in the  Property  other than what has
                  been disclosed in this contract or other writing.

         (e)      Brokers  are not  qualified  to render  property  inspections,
                  survey,s engineering studies,  environmental  assessments,  or
                  inspections to determine compliance with zoning,  governmental
                  regulations, or laws. Buyer should seek experts to render such
                  services.   Selection  of  inspectors  and  repairmen  is  the
                  responsibility of the Buyer and not the Broker.

26.      CONTRACT AS OFFER:  The  execution of this  contract by the first party
         constitutes  an offer to buy or sell the Property.  Unless  accepted by
         the other party by 5:00 p.m. (in the time zone in which the Property is
         located) on FEBRUARY 20, 1997------------------,  the offer shall lapse
         and be null and void.

This is  intended  to be a  legally  binding  contract.  READ IT  CAREFULLY.  NO
REPRESENTATION OR RECOMMENDATION IS MADE BY BROKER OR ITS AGENTS OR EMPLOYEES AS
TO THE LEGAL SUFFICIENCY,  LEGAL EFFECT, OR TAX CONSEQUENCES OF THIS DOCUMENT OR
TRANSACTION.  CONSULT YOUR ATTORNEY BEFORE SIGNING.

Buyer's                                 Seller's
Attorney                                Attorney
        ------------------------                ----------------------------

 /s/ Ron Campbell         2-5-97        /s/ Stanley Jobe             2-11-97
--------------------------------        ------------------------------------
     Ron Campbell                           Stanley Jobe
     Buyer Quality Air Inc.                 Seller

--------------------------------        ------------------------------------



                                       -7-

<PAGE>

Commercial Improved Earnest Money Contract concerning      8909 KINGSWAY
                                                      --------------------------

Buyer                                                                  Seller


--------------------------------------------------------------------------------
                            AGREEMENT BETWEEN BROKERS

Listing Broker agrees to pay -------------------------------------------.  Other
Broker, a fee of  $------------------------ or ----% of the Sales Price when the
Listing Broker's fee is received. Escrow Agent is authorized and directed to pay
Other  Broker from  Listing  Broker's  fee at closing.  This  Agreement  between
Brokers  supersedes  any prior offers and agreements  for  compensation  between
brokers.

                                        John T. Hellard           0142054
--------------------------------        ------------------------------------

Other Broker          License No.       Listing Broker           License No.

By:-----------------------------        By:---------------------------------

                                        3707 Admiral          (915) 593-1957
--------------------------------        ------------------------------------

Other Broker's Address  Phone No.       Listing Broker's Address   Phone No.

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
                                     RECEIPT

On this day,  -----------------------------,  Escrow Agent acknowledges  receipt
of:   (a)  [  ]   Contract;   and  (b)  [  ]  Earnest   Money  in  the  form  of
-----------------------------------
Escrow Agent ------------------------------       By:--------------------------
Address:-----------------------------------     Phone:-------------------------

--------------------------------------------------------------------------------

                                      -8-

<PAGE>

--------------------------------------------------------------------------------
                         HAZARDOUS MATERIALS WARNING AND
                       DISCLAIMER FOR PROPERTIES INVOLVED
                        IN SALE AND/OR LEASE TRANSACTIONS

Property: 8909 KINGSWAY
          ----------------------------------------------------------------------

Various  materials  utilized  in the  construction  of any  improvements  to the
Property may contain materials that have been or may in the future be determined
to be toxic,  hazardous or  undesirable  and may need to be  specially  treated,
specially handled and/or removed from the Property. For example, some electrical
transformer sand other electrical components can contain PCB's, and asbestos has
been used in a wide variety of building  components such as  fire-proofing,  air
duct insulation,  acoustical titles,  spray-on acoustical  materials,  linoleum,
floor  tiles  and  plaster.  Due to  current  or prior  uses,  the  Property  or
improvements  may  contain  materials  such  as  metals,  minerals,   chemicals,
hydrocarbons, biological or radioactive materials and other substances which are
considered,  or in the future may be determined  to be, toxic wastes,  hazardous
materials  or  undesirable   substances.   Such   substances  may  be  above-and
below-ground containers on the Property or may be present on or in soils, water,
building  components or other  portions of the Property in areas that may or may
not be accessible or noticeable.

Current and future federal, state and local laws and regulations may require the
clean-up of such toxic,  hazardous  or  undesirable  materials at the expense of
those  persons who in the past,  present or future have had any  interest in the
Property  including,  but not limited to, current,  past and future users of the
property.  Sellers/lessors  and  Buyers/Tenants  are  advised  to  consult  with
independent legal counsel of their choice to determine their potential liability
with respect to toxic, hazardous, or undesirable materials.  Sellers/lessors and
Buyers/Tenants  should also  consult with such legal  counsel to determine  what
provisions regarding toxic,  hazardous or undesirable materials they may wish to
include  in  purchase  and sale  agreements,  leases,  options  and other  legal
documentation  related  to  transactions  they  contemplate  entering  into with
respect to the Property.

The real estate  salespersons and brokers in this transactions have no expertise
with respect to toxic wastes,  hazardous  materials or  undesirable  substances.
Proper  inspections  to the  property  by  qualified  experts  are  an  absolute
necessity to determine  whether or not there are any current or potential  toxic
wastes, hazardous materials or undesirable substances in or on the Property. The
real estate  salespersons and brokers in this transaction have not made, or will
they make,  any  representations,  either  express  or  implied,  regarding  the
existence or nonexistence of toxic wastes,  hazardous materials,  or undesirable
substances in or on the Property.  problems  involving  toxic wastes,  hazardous
materials,  or undesirable  substances can be extremely costly to correct. It is
the  responsibility of  Sellers/Lessors  and  Buyers/Tenants to retain qualified
experts to deal with the detection and correction of such matters.


SELLER/LESSOR                               BUYER/TENANT

By: /s/ Stanley Jobe                        By: /s/ Ron Campbell
   ---------------------------                 ---------------------------
       STANLEY JOBE                                 RON CAMPBELL

Title:                                               Title: Controller/CFO
   ---------------------------                 ---------------------------
Date:  2-11-97                                       Date:  2-5-97
--------------------------------------------------------------------------------


                                       -9-

<PAGE>

                       ADDENDUM TO EARNEST MONEY CONTRACT

                  The Addendum is made by and between  STANLEY  JOBE  ("Seller")
and QUALITY AIR, INC.  and/or  assigns  ("Buyer") to that certain  Earnest Money
Contract of Sale ("Contract") dated 11th day of February, 1997, for the purchase
and sale of that certain property legally described as follows:

                  Lots 3 to 20, 41 to 58, Block 15, WESTWAY UNIT II, an Addition
                  to El Paso  County,  Texas,  according  to the plat on file in
                  Volume 17, Page 35, Real  Property  Records,  El Paso  County,
                  Texas;  also known as 8989  Kingsway  in the City of  Anthony,
                  Texas.

                  1. The parties  desire to amend the  contract  with regards to
Paragraph  7(a)(1) and  Paragraph II to more  specifically  set out all of their
terms of Buyer's acceptance of the Property.  Said paragraph shall be amended by
adding the following:

                  "CONDITION  OF  PREMISES.   Buyer   acknowledges  that  Seller
acquired the property  through a Deed in Lieu of  Foreclosure  and  consequently
Seller  discloses  that  there  may be some  defects  in the  roof  and the roof
structure.  Further, Seller discloses that the property is not connected to City
water or sewer.  Accordingly,  except as otherwise  specifically  stated herein,
BUYER ACKNOWLEDGES AND AGREES THAT NEITHER THE SELLER NOR THE BROKERS HAVE MADE,
DO  NOT  MAKE  AND  SPECIFICALLY   NEGATE  AND  DISCLAIM  ANY   REPRESENTATIONS,
WARRANTIES,  PROMISES,  COVENANTS,  AGREEMENTS  OR  GUARANTIES  OF ANY  KIND  OR
CHARACTER WHATSOEVER, WHETHER EXPRESS OR IMPLIED, ORAL OR WRITTEN, PAST, PRESENT
OR FUTURE,  OF, AS TO,  CONCERNING  OR WITH  RESPECT  TO (A) THE VALUE,  NATURE,
QUALITY OR CONDITION OF THE PROPERTY,  INCLUDING, WITHOUT LIMITATION, THE WATER,
SOIL AND  GEOLOGY,  (B) THE  INCOME TO BE  DERIVED  FROM THE  PROPERTY,  (C) THE
SUITABILITY  OF THE PROPERTY FOR ANY AND ALL ACTIVITIES AND USES WHICH BUYER MAY
CONDUCT  THEREON,  (D) THE  COMPLIANCE  OF OR BY THE PROPERTY OR ITS  APPLICABLE
GOVERNMENTAL   AUTHORITY  OR  BODY,  (E)  THE   HABITABILITY,   MERCHANTABILITY,
MARKETABILITY,  PROFITABILITY  OR  FITNESS  FOR  A  PARTICULAR  PURPOSE  OF  THE
PROPERTY,  (F) THE MANNER OR QUALITY OF THE  CONSTRUCTION  OR MATERIALS,  IF ANY
INCORPORATED INTO THE PROPERTY, (G) THE MANNER, QUALITY, STATE OF REPAIR OR LACK
OF REPAIR OF THE PROPERTY, OR (H) ANY OTHER MATTER WITH RESPECT TO THE PROPERTY,
AND  SPECIFICALLY,  THAT  SELLER  AND  BROKERS  HAVE NOT  MADE,  DO NOT MAKE AND
SPECIFICALLY   DISCLAIM  ANY  REPRESENTATIONS   REGARDING  COMPLIANCE  WITH  ANY
ENVIRONMENTAL,  PROTECTION,  POLLUTION OR LAND USE,  LAWS,  RULES,  REGULATIONS,
ORDERS  OR  REQUIREMENTS,  INCLUDING  SOLID,  WASTE,  AS  DEFINED  BY  THE  U.S.
ENVIRONMENTAL,  PROTECTION  AGENCY  REGULATIONS  AT 40 C.F.R.,  PART 261, OR THE
DISPOSAL OR  EXISTENCE,  IN OR ON THE PROPERTY OF ANY  HAZARDOUS  SUBSTANCE,  AS
DEFINED BY THE COMPREHENSIVE  ENVIRONMENTAL  RESPONSE COMPENSATION AND LIABILITY
ACT OF 1980, AS AMENDED, AND REGULATIONS PROMULGATED  THEREUNDER.  BUYER FURTHER
INSPECT THE  PROPERTY,  BUYER IS RELYING  SOLE ON ITS OWN  INVESTIGATION  OF THE
PROPERTY  AND NOT ON ANY  INFORMATION  PROVIDED  OR TO BE  PROVIDED BY SELLER OR
BROKER. BUYER FURTHER ACKNOWLEDGES AND




                                      -10-

<PAGE>


AGREES  THAT ANY  INFORMATION  PROVIDED OR TO BE  PROVIDED  WITH  RESPECT TO THE
PROPERTY WAS OBTAINED FROM A VARIETY OF SOURCES AND THAT SELLER AND BROKERS HAVE
NOT MADE ANY INDEPENDENT  INVESTIGATION  OR VERIFICATION OF SUCH INFORMATION AND
MAKE NO  REPRESENTATIONS AS TO THE ACCURACY OR COMPLETENESS OF SUCH INFORMATION.
SELLER IS NOT LIABLE OR BOUND IN ANY MANNER BY ANY VERBAL OR WRITTEN STATEMENTS,
REPRESENTATIONS  OR  INFORMATION  PERTAINING TO THE  PROPERTY,  OR THE OPERATION
HEREIN,  FURNISHED BY ANY REAL ESTATE BROKER, AGENT, EMPLOYEE,  SERVANT OR OTHER
PERSON,  BUYER  FURTHER  ACKNOWLEDGES  AND  AGREES  THAT TO THE  MAXIMUM  EXTENT
PERMITTED  BY LAW, THE SALE OF THE PROPERTY AS PROVIDED FOR HEREIN IS MADE ON AN
"AS IS"  CONDITION AND BASIS WITH ALL FAULTS.  IT IS UNDERSTOOD  AND AGREED THAT
THE PURCHASE PRICE HAS BEEN ADJUSTED BY PRIOR NEGOTIATION TO REFLECT THAT ALL OF
THE PROPERTY IS SOLD BY SELLER AND PURCHASED BY BUYER SUBJECT TO THE  FOREGOING.
THE  PROVISION  OF  THIS  PARAGRAPH  SHALL  BE  INCORPORATED  IN THE  DEED TO BE
DELIVERED AT CLOSING AND SHALL SURVIVE THE CLOSING."

                  2.  REPRESENTATIONS  AND WARRANTIES OF BUYER. Buyer represents
and  warrants  as of the  date  hereof  and as of the  date  of  closing,  which
representations  and warranties shall survive the closing,  that it has the full
corporate  power to enter  into and  consummate  this  transaction  and that the
officer  executing  this  document  and the  documents  at closing has been duly
authorized  and  empowered  to enter  into  this  Agreement  and  consummate  it
according to its terms.

                  3. All other terms and conditions unless modified herein shall
remain in full force and effect.


Dated this 11th day of February, 1997.
           ----

SELLER                                         BUYER
                                               QUALIFY AIR, INC.


By: /s/ Stanley P. Jobe                        By: /s/ Ron Campbell     2-17-97
----------------------------                   ---------------------------------
STANLEY P. JOBE                                        RON CAMPBELL
                                               Its:    Controller




                                      -11-