How to add button that copies the text from a textbox?

Hi,
I wan to add a button, that copies part (or whole) searched part and copies it to the file?
Actually, the only thing I need, is some API, or pointing, which classes are for menu, button and textbox so that I can write it for myself.
Beniamin.
I wan to add a button, that copies part (or whole) searched part and copies it to the file?
Actually, the only thing I need, is some API, or pointing, which classes are for menu, button and textbox so that I can write it for myself.
Beniamin.