[Quark] How to capture key or buttons pressed?

What I want to do:

  1. Launch the print dialog
  2. Let user enter their parameter
  3. Capture the settings onto memory
  4. Then carry on to the printing process

The sample script looks like this:

tell application "QuarkXPress Passport"
	tell document 1
		tell application "System Events"
			tell process "QuarkXPress Passport"
				keystroke "p" using command down
					here is where I need the system to capture user's certain click (eg. click on button "capture Settings")
					and then the script will exit from the loop
					and continue to process
				end repeat
			end tell
		end tell
	end tell
end tell

But I struggled hard yet could not find a solution for key pressed or button pressed then exit from the loop. Hope someone can help me to solve my problem.
Thanks in advance!