function getURLParam(strParamName) {
    var strReturn = "";
    var strHref = window.location.href;
    if (strHref.indexOf("?") > -1) {
        var strQueryString = strHref.substr(strHref.indexOf("?")).toLowerCase();
        var aQueryString = strQueryString.split("&");
        for (var iParam = 0; iParam < aQueryString.length; iParam++) {
            if (aQueryString[iParam].indexOf(strParamName.toLowerCase() + "=") > -1) {
                var aParam = aQueryString[iParam].split("=");
                strReturn = aParam[1];
                break;
            }
        }
    }
    return unescape(strReturn);
}

//alert('w:'+getURLParam('w')+', h:'+getURLParam('h')+', nr:'+getURLParam('nr') );