var already_opened;

function popFile(psFileName) {
	if (!already_opened || already_opened.closed) {
		already_opened = window.open(psFileName, "popup_window", 'top=25,left=50,width=600,height=500,scrollbars=yes');
	}
	else {
		already_opened.focus();
		already_opened.location = psFileName;
	}
}

function CleanUpPage() {
  	if (already_opened && !already_opened.closed) {
  		already_opened.close();
	}
}