js获取地址栏传递过来的某个参数值

function request(key) {
    var url = location.search; //获取url中"?"符后的字串
    var theRequest = {};
    if (url.indexOf("?") != -1) {
        var str = url.substr(1);
        strs = str.split("&");
        for(var i = 0; i < strs.length; i ++) {
            theRequest[strs[i].split("=")[0]] = unescape(strs[i].split("=")[1]);
        }
    }
    return theRequest[key] || null;
}

var id = request('id');//地址栏中的&id=2