function go2dotin(agentid)
{
    dotinUrl = "http://buy.360.cn/umpay/dotin.html";

    //create an iframe to dotin
    timeStamp = "1282865834";
    dotinIframeId = "ifr_" + timeStamp + "_go2dotin";      

    obj = document.createElement("iframe");
    obj.id = dotinIframeId;
    obj.style.border = "none";
    obj.style.height = "0px";
    obj.style.width = "0px";
    obj.style.display = "none";
    document.body.appendChild(obj);   

    //prepare params for dotin 
    str =  "site=buy";
    str += "&u_ip=222.129.33.237";
    str += "&a=" + agentid;
    str += "&h=http://xunyou.360.cn/index.html?a=7131";
        str += "&c=b73582d65c51507a463b20051292a890";      

    da = new Date();
    str += "&ts=" + da.getTime() ;
    
    obj.src = dotinUrl + "?" + str;        
}