PCO program @ 2004/Feb,22
===========
this program converts pixel coordinate on graph screen
into (x,y) coordinate format or vice versa.
===========
Components:
==PCO program itself + pco List.
===========

Usage:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Specify the first element of "pco" list, either 1 or 0.                      +
	*if program encounters 0 in pco string's first element "pco(0)=0",   +
	 then it converts point coordinate into pixel coordinate.            +
	                                                                     +
	*if program encounters 1 in pco string's first element, then it      +
	 processes pixel coordinates into normal (x,y) format.               +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

	So now, if you want to convert pixel coordinate into xy coordinate,
you will have to store your pixel coordinate into "pco" list's 2nd and 3rd
elements. For example, you want to convert pixel coordinate (17,3) into xy coordinate
according to your graph setting, you will do the following:

		17->|_pco(2):3->|_pco(3):prgmPCO

then PCO outputs the pco string, the 4th and 5th element are X and Y coordinates, respectively.

if you want to do the other way, just store 1 to your |_pco(1), and then store 
(x,y) coordinate into |_pco(4) and |_pco(5) accordingly, and run the program. bang!

=============
Error report:
	alexanderelsa@hotmail.com