function impressum(){
		var winw = 400;
		var winh = 620;
		var w = screen.availWidth;
		var h = screen.availHeight;
		//alert(w + ", " + h);
		var xset = (w - winw) / 2;
		var yset = ((h - winh) / 2)-35;
		var fenster = window.open("impressum.html", "impressum", "width="+winw+"px,height="+winh+"px,menubar=no,toolbar=no");
		fenster.moveTo(xset,yset);
		}



        var _client = 'old';
        var browser=navigator.appName;
        var ver=parseInt(navigator.appVersion);
        if (ver >= 3) _client="ok";
        if (browser == "Microsoft Internet Explorer") _client='ie';

        function popup(url,w,h) {
                urllength = url.length;
                winame = url.substring((urllength-9),(urllength-5))
                title = winame
                if (_client == "ok") {
                        winparams = 'toolbar=0,location=0,directories=0,status=0,menubar=0,resizable=0,scrollbars=0,width=' + w + ',height=' + h ;
                        winame = open(url,winame,winparams);
                        history.go(url);
                        document.close()
                        winame.focus();
                 }
                 if (_client == "ie") {
                        baseurl = location.href;
                        winparams = 'toolbar=0,location=0,directories=0,status=0,menubar=0,resizable=0,scrollbars=1,width=' + w + ',height=' + h ;
                        winame = open(url,winame,winparams);
                        document.close();
                        if  (ver > 3) winame.focus();
                 }
                 if (_client == "old") {
                        baseurl = location.href;
                        winparams = 'toolbar=0,location=0,directories=0,status=0,menubar=0,resizable=0,scrollbars=1,width=' + w + ',height=' + h ;
                        winame = open(url,winame,winparams);
                        document.close();
                 }
         }