//Script um die Parameter aus der URL auszulesen
function getURLParam(strParamName){
    var strReturn = "";
    var strHref = window.location.href;
    var bFound = false;
    
    var cmpstring = strParamName + "=";
    var cmplen = cmpstring.length;
    
    if (strHref.indexOf("?") > -1) {
        var strQueryString = strHref.substr(strHref.indexOf("?") + 1);
        var aQueryString = strQueryString.split("&");
        for (var iParam = 0; iParam < aQueryString.length; iParam++) {
            if (aQueryString[iParam].substr(0, cmplen) == cmpstring) {
                var aParam = aQueryString[iParam].split("=");
                strReturn = aParam[1];
                bFound = true;
                break;
            }
        }
    }
    if (bFound == false) 
        return null;
    return strReturn;
}



//AUFRUF:
if (getURLParam("XY") != null) {
    YZ = getURLParam("XY");
}
else {
    YZ = "";
}