function page_btn(currentPage,path,pageSize)
{
   var urlparam="currentPage="+currentPage+"&path="+path+"&pageSize="+pageSize+"&dt="+new Date().getTime();
   var urlStr="Handler.ashx";
   obj_ajax(urlparam,urlStr,page);    
}
function page()
{
    if(xmlHttp.readystate==4)
    {
        if(xmlHttp.status==200)
        {
           var Rt=xmlHttp.responseText; 
           document.getElementById("divHTML").innerHTML=Rt;
        }
    }
}
function chb_box()
{
   var chb=document.getElementsByName("chb");
   for(var i=0;i<chb.length;i++)
   {
       if(chb[i].checked==true)
       {
          return true;
       }
   }
   alert("请选择课程");
   return false;

}