function PopupWindow(app,myWidth,myHeight) {
	myTop = (screen.height/2) - (myHeight/2);
	myLeft = (screen.width/2) - (myWidth/2);
	features = 'height=' + myHeight;
	features += ',width=' + myWidth;
	features += ',top=' + myTop;
	features += ',left=' + myLeft;
	features += ',scrollbars=yes';
	features += ',status=no';
	popup = open(app,'PopupApp',features);
}