var isPopUpOpen = 0;	// Normales PopUp
var jsPopUp;

function popup(page, w, h, sbars) {
	if(sbars == null) {
		sbars = "no"
	}

	/* Überprüfen ob PopUp bereits geöffnet */
	if(isPopUpOpen == 1) {
		jsPopUp.close();
		isPopUpOpen = 0;
	}
				
	jsPopUp = window.open(page, "normal_win", "width="+w+",height="+h+",  left="+((screen.availWidth-w)/2)+", top="+((screen.availHeight-h)/2)+", scrollbars=" + sbars + ",status=0,resizable=0");
	isPopUpOpen = 1;
	jsPopUp.focus();
	return;
}