function showpopup(url,description,width,height) {
 description = description.replace(/ /g,"+");

 var hoehe = width + 60;
 var breite = height + 30;
 var links = (screen.width - breite) / 2;
 var oben = (screen.height - hoehe) / 2;


 var wurl = "http://www.fuxreisen.de/popup.htm?url="
     wurl = wurl.concat(url);
     wurl = wurl.concat("&text="); 
     wurl = wurl.concat(description); 
     
 F1 = window.open(wurl,"Fenster1","left=" + links + ",top=" + oben + ",resizable=yes, width=" + breite + ", height=" + hoehe);
}