I need help again

How to make a computer "Listen" to someone's input and do accordingly?

Basically, if I make a program to label the computer, but I still want to remain within the OS I've made without coming out of it to go to the Computer Craft built in OS. So the program listens for the person's input and labels the computer what that player types. If that makes any sense.

EX:

Please input the label below:
Example
Please wait…
This computer is now labeled "Example"

I know what labeling is. I just needed to know how to do it within a program. :3

Those two posts did absolutely nothing for me. One told me what the read thing did, one told me what labeling was I need to know how to do both of those together in a program. Thanks <3

EDIT: I apologize. I didn't read them both all the way through. Thank you for being patient with me :3