To graph a function you have too use Reverse Polish notation.
example x,2,^ is the same as x^2
commas denote separate items 
ie. when the program comes across a comma it pushes all the proceding data onto the stack and sets the Holder varible to 0. If the preceding data is an operation it pops the two preceding values off the stack and does the operation to them; so if you have x,2,* the program pushes the x and 2 onto the stack and when it comes to the times symbol it pops the 2 and the x off of the stack and multiplies the x by the 2.

here are some more examples of equations.

x,2,* = x*2
x,2,^,2 * = x^2*2
x,3,^,x,2,^,- = x^3-x^2


When you click the value button the program will give you the Y value for the X value thats in the X Value Box.

This is my first Readme so if you can't get it to work email me at Bjwbell@netscape.net