跪求大神，求解DWR注册验证用户，修改错误

DAO层代码 //验证用户名 
public Iclouduser findReigsterName(String name){
Session session = this.getSession();
Iclouduser user = null;
try {
String hql = "from Iclouduser ic where ic.username=:username";
Query query = session.createQuery(hql);
query.setString("username", name);
user = (Iclouduser) query.uniqueResult();
} catch (Exception e) {
e.printStackTrace();
}
return user;
}
------------------
UserReigsterDwr //验证用户方法
public class UserReigsterDwr {
private IclouduserDAO userDao;
//验证用户
public boolean checkReigster(String name) {
boolean bool = false;
try {
Iclouduser user = userDao.findReigsterName(name);
System.out.println("打印++++++++"+user.getUsername());
if (null != user) {
System.out.println("有对象");
bool = true;
} else {
System.out.println("没对象");
bool = false;
}
} catch (Exception e) {
e.printStackTrace();
}
return bool;
}
-----------------------------
jsp页面代码
<script type="text/javascript" src="dwr/engine.js"></script>
<script type="text/javascript" src="dwr/util.js"></script>
<script type="text/javascript" src="dwr/interface/checkReigsterName.js"></script>

function checks(){
var usernawc = document.getElementById("username").value;
checkReigsterName.checkReigster(usernawc,no);
}
function no(boolean){
if(boolean){
alert("已注册");
}else{
alert("没注册")
}
}

<th><span class="must">*</span>用户名：<input type="button" value="测试" onclick="checks()"/></th><td><input class="input_name" type="text" name="icloudUser.username" id="username"
onblur="checkNull(this)" onfocus="checkFocus(this)" maxlength="20"  size="30"/>
--------------------------------
DWR.XML代码
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC
    "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN"
    "http://getahead.org/dwr/dwr20.dtd">
<dwr>
    <allow>
<create creator="new" javascript="checkReigsterName">
<param name="class" value="com.iCloud.dwr.UserReigsterDwr"></param>
<!-- <include method="checkReigsterName" />-->
</create>
</allow>
</dwr>
--------------------------
myeclipse里报的错误：
DEBUG - --Object created,  not stored. id=0
java.lang.NullPointerException
at com.iCloud.dwr.UserReigsterDwr.checkReigster(UserReigsterDwr.java:14)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.directwebremoting.impl.ExecuteAjaxFilter.doFilter(ExecuteAjaxFilter.java:34)<