ajax url的参数怎么传到Action里面

<!-- ajax判断用户名是否存在 -->
<br> var request = false;<br> try{<br> request = new XMLHttpRequest();<br> }catch(microsoftIE){<br> try{<br> request = new ActiveXObject(&quot;Msxml2.XMLHTTP&quot;);<br> }catch(microsoftOldIE){<br> try{<br> request = new ActiveXObject(&quot;Microsoft.XMLHTTP&quot;);<br> }catch(failed){<br> request = false;<br> }<br> }<br> }<br> if(!request){<br> alert(&quot;初始化XMLHttpRequest对象失败&quot;);<br> }<br> function sendUsername(){<br> var username = document.getElementById(&quot;userid&quot;).value;<br> if(username!=null &amp;&amp; username!=&quot;&quot;){<br> [color=blue]var url = &quot;userManageAction!getAdd.action?username=&quot;+escape(username);[/color] // [color=red]怎样把这里的值给Action[/color]<br> alert(url);<br> request.open(&quot;post&quot;,url,true);<br> request.onreadystatechange=updatepage;<br> request.send(null);<br> }<br> }<br> function updatepage(){<br> if(request.readyState==4){<br> if(request.status==200){<br> document.getElementById(&quot;reusername&quot;).innerHTML = request.responseText;<br> //document.getDocumentById(&quot;reusername&quot;).innerText = request.responseText;<br> }else if(request.status==404){<br> alert(&quot;找不到页面！&quot;);<br> }else{<br> alert(&quot;错误代码:&quot;+request.status);<br> }<br> }<br> }<br> function clearMessage(){<br> document.getElementById(&quot;reusername&quot;).innerHTML = &quot;&quot;;<br> }<br>
Struts2 Action代码:
// 判断用户名是否已经存在
if(userManage.getName() != null){
namelist = userManageService.exist(userManage);
for(int i=0;i UserManageVo umv = (UserManageVo)namelist.get(i);
if(userManage.getName().equals(umv.getName())){
this.addActionError("用户名已经注册");
}else {
this.addActionError("用户名可以用");
}
}

    }

[code="java"] var url = "userManageAction!getAdd.action // 这里单纯写URL
alert(url);
request.open("post",url,true);
request.onreadystatechange=updatepage;
request.send("key1=value1&key2=value2");//这里传值
[/code]