var par='.com/'
   var uzai_url=window.location.href;
   $("#cityselect").val(uzai_url.substring(7,uzai_url.indexOf(par)));//设定默认选择项
function option_gourl(a)
    {
    if(a=='bj.uzai')
    {
        window.location.href=bjurl;
     }
    else
    {
        window.location.href='http://'+a+uzai_url.substring(uzai_url.indexOf(par),uzai_url.length);
    }

    }