3.5'' 320x480 TFT Arduino Mega Shield Problem

Hello

Recently I bought a 3.5'' TFT screen.
The controller is R61581.
The touch controller is XPT2046.
I succed to run a code with the UTFT library, but I can't use the touch screen. I'm clicking on the screen, but nothing happened. what can I do in order to use the touch screen?

Thanks.