js获取get值

    //获取get值
    function getPar(par) {
        //获取当前URL
        var local_url = document.location.href;
        //获取要取得的get参数位置
        var get = local_url.indexOf(par + "=");
        if (get == -1) {
            return false;
        }
        //截取字符串
        var get_par = local_url.slice(par.length + get + 1);
        //判断截取后的字符串是否还有其他get参数
        var nextPar = get_par.indexOf("&");
        if (nextPar != -1) {
            get_par = get_par.slice(0, nextPar);
        }
        return get_par;
    }
    window.onload = function () {
       alert(getPar("XL"));
   }