function BrowserCheck() {
        		var b = navigator.appName
				var c = navigator.userAgent // WEIL OPERA SICH ALS INTERNET EXPLORER MELDET BENUTZEN WIR userAgent STATT appName
				var p = navigator.platform
				if (c.indexOf("Opera")!=-1) this.c = "op"
				else if ((b=="Netscape") && (p.indexOf("Mac")!=-1)) this.b = "nsmac"
				else if (b=="Netscape") this.b = "ns"
				else if ((b=="Microsoft Internet Explorer") && (p.indexOf("Mac")!=-1)) this.b = "iemac"
				else if (b=="Microsoft Internet Explorer") this.b = "ie"
				else this.b = b
        		this.v = parseInt(navigator.appVersion)
        		this.ns = ((this.b=="ns" && this.v>=4)||(this.b=="nsmac" && this.v>=5))
        		this.ie = ((this.b=="ie" && this.v>=4)||(this.b=="iemac" && c.substr(c.indexOf("MSIE ")+5,3)>=5))
				this.op = (this.c=="op" && this.v>=4)
				this.ns4mac = (this.b=="nsmac" && this.v==4)
				this.ie4mac = (this.b=="iemac" && c.substr(c.indexOf("MSIE ")+5,3)<5)
		}
		
		is = new BrowserCheck();
		
		function getAttr(height,width){
		if (is.op){
         		vitawinleft = (screen.width - width) / 2;
        		vitawintop = 10;
         		var attr = "left=" + vitawinleft + ",top=" + vitawintop + ",width=" + width + ",height=" + height;
      		} else if (is.ie||is.ie4mac){
         		vitawinleft = (screen.width - width) / 2;
        		vitawintop = (screen.height - height) / 2;
         		var attr = "left=" + vitawinleft + ",top=" + vitawintop + ",width=" + width + ",height=" + height;
			} else if (is.ns||is.ns4mac) {
        		vitawinleft = window.screenX + ((window.outerWidth - width) / 2);
         		vitawintop = window.screenY + ((window.outerHeight - height) / 2);
         		var attr = "screenX=" + vitawinleft + ",screenY=" + vitawintop + ",width=" + width + ",height=" + height;
      		} else {
         		var attr = "width=" + width + ",height=" + height;
      		}
      	return (attr);
		}
		
		function popup(height,width,seite,name) {
			if (navigator.appVersion.charAt(0)< '4') {
				this.location = 'sorrypage.html';
			}else{
				attr=getAttr(height,width);
				vitawin = window.open(seite,name,"toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=0,resizable=0," + attr);
				vitawin.focus();
			}
		}