comparing a variable from a matrix

I wish for the user to input a matrix, and then use a user defined function to take out the two numbers and then input them into a compare to constant block.

[Geoff]

Cool. How far have you got with your code?

[john]

I am really not that great at explaining my problems, it would be a lot easier if i could show you them but i don't see any way of adding an attachment.