javascript - How to access Struct framework ( JSP ) form variable for Ajax query -

please help. have implemented registration form of website using struct framework validation.

  <html:form action="servletregister.do" method="post" style="width: 95%">   <tr>        <td>user id : * </td>        <td><html:text property="userid" /> <html:errors property="userid"/></td>         td> <html:button property="button" value="check availability" style="color:#ffffff; background-color: #11bdd1; width: 130px;" onclick="test();" />           <div id="ajax"> // ajax query result show           </div>   </tr>      

problem is, want validate userid using ajax .

 function test(){             var userid = document.getelementbyid("userid").value;             if(userid=="")                 {                       alert("please enter userid");                 }              else {                        var xmlhttp = new xmlhttprequest();                      xmlhttp.onreadystatechange = function(){                         var content = document.getelementbyid("ajax");                         content.innerhtml = xmlhttp.responsetext;                     }                     //xmlhttp.open("get","table.jsp?num="+num,true);                     //xmlhttp.send(null);                      xmlhttp.open("post","validate.jsp",true);                     xmlhttp.setrequestheader("content-type","application/x-www-form-urlencoded");                     xmlhttp.send("userid="+userid);              }         } 

if dont use structs , easy access user id dom object. unable figure out how access struct user id textfield in javascript. please :)

in struts styleid attribute renders "id" attribute.so change code shown below

<html:text property="userid" styleid="userid" />  

reference:http://struts.apache.org/development/1.x/struts-taglib/tlddoc/html/text.html