how to control a buttons with parallel port interfacing

[rapperhuj]

hi,

how to control a button that is, if you click it.. example.. button "A", then the data inputs will
construct a binary bits and output the seven segment with letter A..

and
i am constructing a program that the user will input a string on the textbox then the seven segment on the parallel port interfacing (output) will display all the characters that the user type.. in it is scrolling until the whole characters is been display..

sir ..maam ,
pls give me some hints or tips how to save a data then output it on the parallel ports..
thnks..

by the way i"m using led to see the output binary bits of my program thnks.. a lot