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: 
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an external supply system, and more particularly to an external supply system, wherein the supply device co-operates with the sensing device to provide the cleaning agent and the flush water synchronously, thereby facilitating the user washing and cleaning the object.  
           [0003]    2. Description of the Related Art  
           [0004]    A conventional supply device  40  in accordance with the prior art shown in FIG. 6 contains liquid, such as the cleaning agent or the like therein. In arrangement, the supply device  40  is spaced away from the faucet  50 , so that the user has to take the cleaning agent from the supply device  40  and then clean his hands by water released from the faucet  50  that is located far away from the supply device  40 , thereby causing inconvenience to the user.  
         SUMMARY OF THE INVENTION  
         [0005]    The primary objective of the present invention is to provide an external supply system comprising a supply device for providing the cleaning agent, and a sensing device for providing the flush water automatically.  
           [0006]    Another objective of the present invention is to provide an external supply system, wherein the supply device is connected to the sensing device, so that the water flowing outward from the water outlet of the sensing device can synchronously co-operate with the cleaning agent flowing outward from the supply device to wash and clean the object.  
           [0007]    A further objective of the present invention is to provide an external supply system, wherein the supply device co-operates with the sensing device to provide the cleaning agent and the flush water synchronously, thereby facilitating the user washing and cleaning the object.  
           [0008]    In accordance with the present invention, there is provided an external supply system, comprising a sensing device to provide flush water automatically, and a supply device to provide cleaning liquid, wherein:  
           [0009]    the supply device is connected to the sensing device to provide the flush water and the cleaning liquid synchronously.  
           [0010]    Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of an external supply system in accordance with the preferred embodiment of the present invention;  
         [0012]    [0012]FIG. 2 is a partially cut-away side plan cross-sectional view of the external supply system as shown in FIG. 1;  
         [0013]    [0013]FIG. 3 is a schematic operational view of the external supply system as shown in FIG. 2 in use;  
         [0014]    [0014]FIG. 4 is a schematic operational view of the external supply system as shown in FIG. 1 in use;  
         [0015]    [0015]FIG. 5 is a schematic operational view of the external supply system as shown in FIG. 1 in use; and  
         [0016]    [0016]FIG. 6 is a perspective view of a conventional supply device in accordance with the prior art. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    Referring to the drawings and initially to FIGS. 1-3, an external supply system in accordance with the preferred embodiment of the present invention comprises a sensing device  10 , and a supply device  20 .  
         [0018]    The sensing device  10  has a first side provided with a water inlet  11  and a second side provided with a water outlet  12 . The water inlet  11  of the sensing device  10  is locked on an outlet  32  of a faucet  30 .  
         [0019]    The supply device  20  is connected to the sensing device  10 . The supply device  20  includes a body  21 , a press member  22 , an O-shaped sealing member  224 , an elastic member  223 , and a stop ball  24 . The body  21  of the supply device  20  is substantially cylindrical shaped. The body  21  of the supply device  20  has an inside formed with a receiving chamber  210  containing liquid, such as the cleaning agent or the like therein. The body  21  of the supply device  20  has a bottom formed with a drop hole  202  and has a top provided with a transparent cover  201  to facilitate the user replenishing the cleaning agent. The receiving chamber  210  of the body  21  of the supply device  20  has a bottom formed with a connecting hole  212 .  
         [0020]    The body  21  of the supply device  20  has a lower portion provided with a cylinder  23  having an inside formed with an operation space  230 . The operation space  230  of the cylinder  23  has a first side communicating with the receiving chamber  210  through the connecting hole  212  of the receiving chamber  210  and a second side formed with a passage  232  communicating with the drop hole  202  of the body  21 .  
         [0021]    The press member  22  of the supply device  20  is movably mounted on the body  21  and has a first end  221  protruded outward from the body  21  and a second end  222  slidably mounted in the operation space  230  of the cylinder  23 . The second end  222  of the press member  22  has a diameter flush with that of the operation space  230  of the cylinder  23 .  
         [0022]    The sealing member  224  of the supply device  20  is mounted on the press member  22  to move therewith and is rested on a first side of the second end  222  of the press member  22 .  
         [0023]    The elastic member  223  of the supply device  20  is mounted in the operation space  230  of the cylinder  23  and is rested on the press member  22  to press the press member  22  to move the sealing member  224 .  
         [0024]    Thus, the sealing member  224  is driven by the press member  22  to move between a first position as shown in FIG. 2 where the sealing member  224  closes and seals the passage  232 , thereby disconnecting the operation space  230  of the cylinder  23  with the drop hole  202  of the body  21 , and a second position as shown in FIG. 3 where the sealing member  224  is detached from the passage  232 , thereby connecting the operation space  230  of the cylinder  23  with the drop hole  202  of the body  21 .  
         [0025]    The elastic member  223  of the supply device  20  has a first end rested on a second side of the second end  222  of the press member  22  and a second end rested on a side of the operation space  230  of the cylinder  23 .  
         [0026]    The stop ball  24  of the supply device  20  is movably mounted in the connecting hole  212  of the receiving chamber  210  of the body  21 .  
         [0027]    In operation, the press member  22  is initially pressed by the elastic member  223  to move outward, so that the sealing member  224  is driven by the press member  22  to move to the first position as shown in FIG. 2 where the sealing member  224  closes and seals the passage  232 , thereby disconnecting the operation space  230  of the cylinder  23  with the drop hole  202  of the body  21 , thereby preventing the cleaning agent from flowing outward through the passage  232  and the drop hole  202 . At the same time, the stop ball  24  seals the connecting hole  212  of the receiving chamber  210  of the body  21 , so that the cleaning agent contained in the receiving chamber  210  of the body  21  will not enter the operation space  230  of the cylinder  23 .  
         [0028]    On the contrary, when the press member  22  is pressed by the user to move inward, the sealing member  224  is driven by the press member  22  to move to the second position as shown in FIG. 3 where the sealing member  224  is detached from the passage  232 , thereby connecting the operation space  230  of the cylinder  23  with the drop hole  202  of the body  21 .  
         [0029]    At the same time, the operation space  230  of the cylinder  23  produces a pressure to push the stop ball  24  upward during movement of the press member  22 , thereby detaching the stop ball  24  from the connecting hole  212  of the receiving chamber  210  of the body  21  and thereby connecting the receiving chamber  210  of the body  21  with the operation space  230  of the cylinder  23 , so that the cleaning agent contained in the receiving chamber  210  of the body  21  can enter the operation space  230  of the cylinder  23  through the connecting hole  212 .  
         [0030]    After the press force applied on the press member  22  is removed, the press member  22  is pressed by the restoring force of the elastic member  223  to move outward, so that the sealing member  224  and the cleaning agent are pressed by the second end  222  of the press member  22  to move to the first position as shown in FIG. 2, thereby squeezing the cleaning agent outward through the passage  232  and the drop hole  202  as shown in FIGS. 2 and 4.  
         [0031]    When the sensing device  10  detects existence of an object, the sensing device  10  sends a signal to an electromagnetic valve (not shown) which controls the water to flow outward from the water outlet  12  of the sensing device  10  as shown in FIG. 5, so as to co-operate with the cleaning agent flowing outward from the supply device  20  to wash and clean the object.  
         [0032]    Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.

Summary:
An external supply system includes a sensing device to provide flush water automatically, and a supply device to provide cleaning liquid. The supply device is connected to the sensing device to provide the flush water and the cleaning liquid. Thus, the supply device co-operates with the sensing device to provide the cleaning agent and the flush water synchronously, thereby facilitating the user washing and cleaning the object.