function removeDWD() {
    document.getElementById("weather").style.display = "none";
    document.getElementById("weather").innerHTML = "";
}

function showDWD() {

        if (window.XMLHttpRequest) {
            http = new XMLHttpRequest();
        } else if (window.ActiveXObject) {
            http = new ActiveXObject("Microsoft.XMLHTTP");
        }

       if (http != null) {
          http.open("GET", "dwd.php", true);
          http.onreadystatechange = setDWD;
          http.send(null);
       }
}

function setDWD() {
       if (http.readyState == 4) {
          var daten = http.responseText;

          if (daten != "No Match")
          {
            $("weather").innerHTML = daten+'<div style="margin-bottom:0px; position:relative; width:99%; overflow:hidden; z-index:5; text-align:center;"><a href="javascript:removeDWD();" style="display: block; background-color: #bbb;">beenden</a></div>';
            $("weather").style.display = "block";
          }
       }
    }