function openReferer(url) {
     for (var i = 0; i < document.getElementsByName("text").length ; i++) {
        if (document.getElementsByName("text")[i].style.display = "inline") {
           document.getElementsByName("text")[i].style.display = "none";
           document.getElementsByName("code")[i].style.display = "inline";
           document.getElementById("vorschau").style.display = "inline";
           document.getElementById("linkframe").style.display = "block";
           document.getElementById("linkframe").src = url;
       }
    }
  }