How to check what a player wrote in a dialog

So, the title bassicly says everything, I'm currently working a very detailed admin script and I have created

a control panel dialog and what I'd like to know is.

That when an admin presses the Kick a Player option it'll show him a dialog asking for the ID that I already did.

But how do I like get the response from it and check if the ID == INVALID_PLAYER_ID or after that when the

admin is supposed to write the reason etc, do I need to use strcmp? strfind? Well, I don't know.

I'm looking for an answer quick because it's kind of stopping the development of the admin script.

Thanks if anyone helps :)