var winpop;
function popup(url,winBreite,winHoehe, menu, posLinks, posTop) 
{	var screenBreite = (screen.availWidth) ? screen.availWidth : 800;
	var screenHoehe = (screen.availHeight) ? screen.availHeight : 600;
	if ((winBreite == null) || (winBreite <= 100) || (winBreite > screenBreite)) winBreite = screenBreite - 100;
	if ((winHoehe == null) || (winHoehe <= 100) || (winHoehe > screenHoehe-75)) winHoehe = screenHoehe - 75;

	if ( (posLinks == null) || (posLinks < 0) || (screenBreite < posLinks + winBreite) ) posLinks = (screenBreite - winBreite) / 2; // mitte des bildschirms
	if ( (posTop == null) || (posTop < 0) || (screenHoehe < posTop + winHoehe) ) posTop = (screenHoehe - winHoehe) / 2 - 20; // mitte des bildschirms
	if (posTop < 0) posTop = 0;
	if ((menu != 0) && (menu != 1)) menu = 0;

	if (winpop && (winpop.closed != true)) winpop.close();
	winpop = window.open(url,'w','toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=1,resizable=0,width='+winBreite+',height='+winHoehe+',left='+posLinks+',top='+posTop);
	winpop.focus();

	if (winpop.opener == null) {
		self.name='text';
		winpop.opener = self;
	}
	return false;
}

function popupclose()
{
  window.close();
}