You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
FIELD OF INVENTION 
     This invention relates generally to door jambs, and more specifically to a door jamb assembly having a multi-component design allowing for customizability by combining the various components for each specific order such as color, doorway size, or exterior trim style. 
     BACKGROUND OF THE INVENTION 
     The present invention is a doorjamb assembly having an interchangeable multi-component design allowing for customizability of each individual doorway by combining various components. Each differences in configuration of each doorway(such as size, wall width, trim design, etc., can be specifically ordered and attached to the door jamb assembly as to conform not only with the doorway but also the thickness of the wall. In addition, once installed, the doorjamb assembly requires no further finishing. If the door jamb is composed of a material such as high density polyurethane the assembly will also likely be maintenance free. In addition the door jamb assembly can be mated with itself to provide for a sash support. 
     BRIEF DESCRIPTION OF THE PRIOR ART 
     U.S. Pat. No. 5,634,303 discloses an improved door jamb and brickmold assembly having a wooded or plastic jamb and a unitary extruded thermoplastic brickmold and stop. 
     U.S. Pat. No. 4,631,866 discloses an improved door jamb construction adapted to be used with left or right-handed door installations. 
     U.S. Pat. No. 4,295,299 discloses a door frame constructed primarily of wood, and having a metal cladding surrounding a portion of the frame. 
     U.S. Pat. No. 4,330,972 discloses a door frame for mounting pre-hung doors in door openings of an existing structure. 
     U.S. Pat. No. 5,575,123 discloses a vinyl door frame assembly. 
     U.S. Pat. No. 4,180,944 discloses a door jamb made of a plurality of sections which are maintained together in a rigid stable frame. 
     U.S. Pat. No. 4,019,303 discloses a process for making an adjustable split door frame. 
     U.S. Pat. No. 4,126,975 discloses a casing construction for secure mounting in wall openings. 
     SUMMARY OF THE INVENTION 
     Briefly, the present invention comprises a door jamb assembly having a main frame having a face, a first end and a second end providing for the attachment of a door jamb thereto by a fastener. Protruding from the first end of the main frame is an extension for engaging a portion of a decorative trim. A seal can be connected to the face of the extension to provide a weatherproof seal with the decorative trim. Extending from the second end of the main frame and sufficient to overlap a portion of a door jamb is a lip. Located within the door jamb assembly is a member for securing an attachment flange. The attachment flange, once connected to the member then secures the door jamb assembly onto a wall. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a cross-sectional view of a door jamb assembly with a nailing flange secured to the main frame; 
     FIG. 2 shows a cross-sectional view of a door jamb assembly with the nailing flange secured to the trim; 
     FIG. 3 shows a sectional view of a door jamb assembly with the main frame having no leg; 
     FIG. 4 shows a cross-sectional view of a door jamb assembly with the main frame having 2 legs; 
     FIG. 5 shows a cross-sectional view of a door jamb assembly with the decorative trim only having one leg; 
     FIG. 6 shows a cross-sectional view of a door jamb assembly with the decorative trim having a long embodiment; 
     FIG. 7 shows a perspective view of a doorway frame with a side light; 
     FIG. 8 shows a cross-sectional view taken along the lines  8 — 8 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a cross-sectional view of a door jamb assembly  10  that embodies es the present invention in the preferred form. The complete assembly of the present invention comprises four parts, a main frame  11 , an interior door jamb  21 , a decorative trim  18 , and a hinged nailing flange  20 . The end-two-end combination of these parts encompasses a doorway opening on the sides and top to create a substantially maintenance free decorative finish. 
     Door jamb assembly  10  comprises an elongated main frame  11  preferably composed of high density polyurethane but can also be made out of wood or the like. The advantage of using high density polyurethane is that the it can be cut to size much like wood and it requires little if any maintenance. Main frame  11  has a smooth face  11   a  which provides for a decorative looking surface, a first main frame end  31   a  for attachment of decorative trim  18  thereto, and a second main frame end  31   b  which provides for the cantilevered attachment of a jamb  21  by a screw fastener  23 . 
     Protruding outward from the first end  31   a  of main frame  11  is a main frame extension  15  having an end  15   a  for engaging a portion of a trim  18  to create a weather proof seal and a face  15   b  to provide for the attachment of trim  18  by a screw fastener  19 . Extending from the second end  31   b  of main frame  11  is a main frame lip  16  having a jamb engaging face  16   a . Main frame lip  16  extends sufficiently to overlap a portion of door jamb  22  with the door jamb  22  cantileverly attached to end  31   b  by screw fastener  23 . 
     In the embodiment of FIG. 1 main frame  11  has a first main frame leg  12  having a wall engaging end  12   a  located proximate to end  31   a  of main frame  11 , a second leg  13  having a wall engaging end  13   a  located proximate to end  31   b  of main frame  11 , and a third leg  14  having a wall engaging end  14   a  which is located between the first leg  12  and the second leg  13  of main frame  11 . Located at the end  12   a  of first leg  12  is a first member  17  comprising a slot having parallel spaced sidewalls  17   a  and  17   b  extending inwardly for securing a nailing flange thereto. Although the preferred embodiment calls for three legs, there can be more than and less than three legs. 
     Securely attached to main frame  11  at the second main frame leg  13  by a screw fastener  23  is interior jamb  21  having an interior jamb end  21   a . Interior jamb  21  is composed of a veneered lumber core to provide a finished look that does not require further finishing; however, if desired interior jamb  21  can also be made out of other materials such as wood and plastic. Located proximate to end  21   a  of interior jamb  21  is a recess  22  which allows interior jamb end  21   a  to be secured to main frame  11  by first fastener  23  which extends lengthwise along jamb  21  and into leg  13 . As can be seen the jamb  21  and main frame  11  extend in a straight line for placement against one side of a building wall. Jamb  21  is secured to main frame  11  in an end to end fashion in a method described in my U.S. Pat. No. 5,485,708 which is incorporated herein by reference. 
     Securely attached to main frame  11  at extension  15  by second fastener  19  is decorative trim  18  having a decorative exterior face  18   a . Decorative trim  18  is composed of high density polyurethane to provide a weather resistance trim due to polyurethane&#39;s durable weather resistant qualities; however, if desired decorative trim  18  can also be composed of other materials such as wood. The embodiment of FIG. 1 shows decorative trim  18  has a first trim leg  30  having an end  30   a  and a support face  30   b  which is secured to face  15   b  of main frame extension  15  by screw fastener  19 , and a second trim leg  35  having an end  35   a . While the embodiment of FIG. 1 shows two legs there can be more than and less than two legs on decorative trim  18 . Located on leg  30  is a fastener guiding hole  37  which maintains a fastener, such as a screw fastener, in position to pull decorative trim  18  into engagement with main frame  11 . Aligned with fastener guiding hole  37  on second leg  35  is a fastener access hole  36 . Fastener access hole.  36  allows an operator to quickly secure a fastener such as a screw fastener  37  when the screw fastener has been pre-placed within fastener guiding, hole  15  and ready for securement. That is, the fastener guiding hole has a diameter that is sufficiently small so that the screw fastener  37  engages the sidewalls of the fastener guiding holes to frictionally hold screw fastener  37  in a ready to apply condition. The installer need not spend time inserting the fastener since the decorative trim  18  can be sent from the factory with the screw fastener  37  in place for quick installment. Also located on second trim leg  35  is a second member  25  comprising a slot having parallel sidewalls  25   a  and  25   b  for securing a fastening flange such as a nailing flange thereto. 
     Protruding at a right angle to trim leg  30  is a trim lip  26  having a face  26   a  sufficient to overlap a portion of main frame  11 . Attached to the face  26   a  of trim lip  26  is a foam tape  24  having an adhesive on one side for securing foam tape  24  to face  26   a  of trim lip  26 . Foam tape  24  is composed of a closed cell foam that is compressible and water resistant and forms a weather proof seal when trim lip  26  engages with a portion of main frame  11 . Thus with the use of a weather seal the main flame  11  and trim  18  can be sealed to each other to prevent moisture penetration therebetween. 
     As shown in FIG. 1 secured by first member  17  is a hinged nailing or fastening flange  20 . Flange  20  comprises a nailing flange, which is composed of a rigid vinyl, that is connectable either to first member  17  or second member  25  to secure the door jamb assembly to the wall. Nailing flange  20  is a commercially available product and is described in U.S. Pat. No. 4,821,472. 
     With the embodiment of FIG. 1 the present invention provides for two surface support for both jamb  21  and trim  18 . That is, jamb  21  is supported on end  21   a  and surface  21   b  by main frame  11 . Similarly, trim  18  is supported on extension surface  15   b  and on extension end  15   a  of main frame  11 . Main frame  11  and jamb  21  thus provide an elongated section for placing against a first wall while the trim  18  provides an angular protrusion for engaging against a second wall with the trim supportable by the main frame and the entire assembly  10  supportable by a fastening flange securable to either the main frame  11  or the trim  18 . 
     FIG. 2 shows a cross-sectional view of a door jamb assembly  10  which is almost identical to FIG. 1 except that nailing flange  20  is secured by second member  25  instead of first member  17 . The ability to secure nailing flange  20  either at first member  17  or second member  25  provides flexibility in mounting door jamb assembly  10 . Placing nailing flange at first member  12  allows the operator to secure main frame  11  to a wall before having to choose a decorative trim. For trims with wide widths, placing nailing flange  20  at first member  12  also allow the trim to hide the fasteners used to secure nailing flange  20  to the wall. On the other hand, placing nailing flange  20  at second member  25  allows the operator to secure the door jamb assembly  10  as a unit to a building wall by nailing through flange  20  and into the building wall. One of the features of the present invention is that the trim leg  36  can be cut to sufficient length to engage a wall board. Thus the amount of inventory of trim can be reduced because the trim can be cut to fit different thickness wallboards. 
     FIG. 3 shows a cross sectional view of a door jamb assembly similar to FIG. 2 except that main frame  11  does not have any legs. The first member for securing nailing hinge  20  is located proximate first end  31   a  of main frame  11 . This embodiment could be used for doorways that tend to be narrow in width. 
     FIG. 4 shows a cross sectional view of a door jamb assembly similar to FIG. 2 except that main frame  11  has two legs instead of three. This embodiment can be used for doorways that have a width longer than the embodiment with no legs as in FIG. 3 but shorter than the embodiment with three legs as is shown in FIG.  2 . 
     FIG. 5 shows a cross sectional view of a door jamb assembly similar to FIG. 2 except that decorative trim  38  has one leg  40 . The use of this embodiment is ideal in situations where the doorway is located proximate the corner of a room in which there would not be room to have wider trims or if the user desired a narrower trim. In the embodiment of FIG. 5 the decorative trim includes a screw fastener  37  which is frictionally held in leg  40  in a recessed condition so that the head of screw fastener is located below surface  40   c.    
     FIG. 6 shows a cross sectional view of a door jamb assembly similar to FIG. 2 except that a different decorative trim  48  which is wider than the decorative trim  18  embodiment in FIG.  2 . The use of this embodiment is ideal in situations where the user wants to hide nailing flange  20  after nailing flange  20 , placed at first member  17 , has been used to secure the door jamb assembly to the wall since decorative window trim  18 , in this embodiment, is wider than nailing flange  20 . In addition, since decorative trim  18  is wider than the embodiment in FIG. 2, the additional width provides for extra space for additional art work on the trim. Thus it will be appreciated that with the present invention the door jamb assembly can be construed of many different shapes and sizes through the use of only a few components thereby minimizing the inventory of components for the fabricator. 
     The flexibility of being able to use different type of trims in the door jamb assembly is one of the great advantages of the present invention because it provides the operator the advantage of being able to place a trim on almost all types of doorways, even on doorways which may be located close to the corner of a building. In addition, the operator can also choose from a variety of trim decorations to blend in with the surroundings of the building. 
     FIG. 7 shows a perspective view of a doorway frame with a sidelight wherein the door jamb assembly that is used for the door frame is also used to support a sash and FIG. 8 shows the double door jamb assembly  60  as both a door support and a window sash support. FIG. 8 is a cross sectional view taken along the lines  8 — 8  showing the attachment of first door jamb assembly  10   a  and second door jamb assembly  10   b . In this embodiment a first door jamb assembly  10   a  and a second door jamb assembly are secured together to give support for both the sidelight panel  46  and the door. A mull cap  42 , preferably composed of polyurethane but can also be made out of other materials such as wood or the like, is attached to the outside of the frame to provide for a decorative finish. 
     FIG. 8 shows the two assemblies are attached in such a way that the end faces of their legs are engaging each other. Securely connecting the two assemblies  10   a  and  10   b  together is a mull spline  40  composed of vinyl. Mull spline  40  is attached at the first member  17   a  of first door jamb assembly  10   a  and at the first member  17   b  of second door jamb assembly  10   b . The attachment of the two assemblies  10   a  and  10   b  create a recess  42  located between the extensions  15  and  15 ′ of the two assemblies. A caulk  41  is then applied to the end  42   a  of recess  42  to seal the connection between the two assemblies  10   a  and  10   b.    
     A mull cap trim  43  is then fit into recess  42  with lips  45  and  45 ′ of mull cap trim  43  engaging end  31   a  and  31   a ′ of the main frame extensions. Mull cap trim  43  is preferably composed of high density polyurethane since it can be readily machine and is resistant to moisture penetration thus will not rot but other materials such as wood or the like can be used. The use of mull cap trim  43  not only hides the connection made between the two assemblies but also provides for a decorative finish to the exterior of the side light mull. Securing mull cap trim  43  to the end of the main frame extensions is a double sided tape  44  and  45 ′. Tape  44  and tape  45 ′ are compressible and water resistant and creates a waterproof seal between the connection of mull cap trim  43  to the door jamb assemblies. 
     Located at the second end of the interior jambs  21  and  22  is a decorative mull casing  44 . Mull casing  44  is preferable composed of wood but can be made from other materials such as high density polyurethane and can be attached to the second end of the interior jamb by an adhesive or other type of fastener. Attachment of mull casing  44  not only secures the jambs but hides the junction of the interior jambs by the connection of the two assemblies but also provides for a decorative finish for the interior ends of the door jamb assemblies  10   a  and  10   b  which form side light mull  60 . 
     Located at a right angle to the second end  21   b  of first interior jamb  21  is a side light sash stop  46 . Sash stop  46  is preferably composed of wood but other materials such as polyurethane can be used and can be attached to interior jamb  21  by an adhesive. The function of sash stop  46  is to secure a side light panel  48  in place when side light panel  48  engages door jamb  21 . Located on the opposite end of sash  48  is a second sash support  52  that resiliently supports and cushions window sash  48  against main frame  11 . Although there are two interior jambs shown in this embodiment, the side light mull assembly  60  can be made with one interior jamb of wider width if desired; however the use of interior jambs that are also used for the door jamb allows for the fabricator to maintain a minimum of components. 
     The present invention can thus be used for a doorway trim by securing the door jamb assembly onto a wall or can be used as a side light mull by the use of two main frames securely engaging each other. 
     In the method of assembly a fabricator secures a door jamb to a main frame  11  in an end-to-end condition with at least two surfaces of the main frame engaging door jamb  21 . The user can then secure the door jamb  21  and main frame  11  against a building wall. Once secured against a wall the user can select and attach a decorative trim  18  to the main frame to thereby secure the door jamb assembly as a unit to the building wall. 
     In the step of securing a fastening flange the user can place a nailing flange in either the main frame  11  or the decorative trim  18  and fasten the nailing flange to the building wall. 
     In the step of securing the door jamb  21  to the main frame  11  the fabricator extends a screw fastener  23  through an end of the door jamb  21  and into an end  31   b  of the main frame  11 . 
     In the step of attaching the decorative trim  18  the fabricator laterally secures a leg  30   a  of the decorative trim  18  with a screw fastener  19  with the screw fastener concealed from frontal view. 
     In order to make the door jamb assembly rigid and self supporting the main frame  11  is made from a first material and the door jamb  21  is made of a second rigid material. The attachment of the two material to each other provides additional rigidity to the combination which enables the main frame  11  and door jamb  21  to form a unitary rigid elongated member for placing against a building wall.

Summary:
A door jamb assembly having a interchangeable multi-component design allowing for the framing of doorways with different configurations by first selecting a main frame and a decorative trim that conforms with the doorway and then securing the first end of the main frame, being attached to the decorative trim, onto a wall with the use of an attachment flange and securing the second end of the main frame to an interior jamb with the use of a fastener.