Whenever I can't figure out a Keypressed I usually use the following script:
PHP Code:
//#CLIENTSIDE
function onKeyPressed(keycode,keystring,scancode) {
echo("Keycode: " @ keycode);
echo("Keystring: " @ keystring);
echo("Scancode: " @ scancode);
}
Then from there you can find the right keycode or scancode and form the proper if statement.
Edit: Looks like Switch already posted that.