// popup fenster welches in der mitte des bildschirms zentriert,
// und falls zu gross für die entsprechende auflösung angepasst wird.
function singlePopUp(url,width,height,scroll){
	if(height>window.screen.height) { var height = window.screen.height-60; var width2 = parseInt(width); width2 += 16; width2 = width2.toString(); var scroll = 'yes'; }
	else { var width2 = width; if(!scroll) var scroll = 'no'; }
	var winl = (screen.width-width2)/2 - 4; var wint = (screen.height-height)/2 + 6;
	var singlePopUp = window.open(url,"popUp","width=" + width2 + ",height=" + height + ",top=" + wint + ",left=" + winl + ",scrollbars=" + scroll + ",menubar=no,location=yes,directories=no,resizable=no,status=no");
	singlePopUp.focus();
}