stop SikuliX Script instant

Hello, I've created my own programm. I'm trying to code, that the script should stop instant, if I press "ESC", but the IDE should not be closed. I've tried to set a variable to False if I press ESC, but the while loop only stops, at the start of the loop. I want to stop instant, irrelevant where the loop is. Can anyone help me with this problem? Thank you!