i have tried some code that centers a javascript popup window on the user's screen, but have not had success. can anyone help me modify my code so that this can happen?

Code:
on (release) {
	getURL ("javascript:NewWindow=window.open('eLL_re75_menu_process_pla.asp','lesson','width=780,height=535,left=0,top=0,toolbar=No,location=No,scrollbars=No,status=No,resizable=No,fullscreen=No'); NewWindow.focus(); void(0);");
	gotoAndStop(1);
}
thanks, nords.