entering text into field using mouse clicks

I want to create an on-screen keyboard to enter text into a text field. Basically, click the letter Q and a Q is displayed. I am new to PHP so any detailed instructions would be helpful.

First you didn't explain very well...cuz if you click Q a Q will be displayed...(You did type it! :p ) and Secondly, I think your looking for a JavaScript NOT a PHP scritpt...PHP is serverside.. :D

it'll indeed be something clientsided.

i'm sure these things already exists so why create it yourself?