problem in adding field to database

Dears,
When the user try to register the site , his/her information should write in database.My problem is,it gives me nullPointerException .Before fields add to database , it prints all content true but i don't know why this exception eccure:

javax.servlet.ServletException: #{dbBean.addUser}: javax.faces.el.EvaluationException: java.lang.NullPointerException
javax.faces.webapp.FacesServlet.service(FacesServlet.java:209)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:368)

--------------------------------------------------------------------------
register.jsp

<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="Content-Type"
content="text/html; charset=iso-8859-1" />
<title>Home Page</title>
<link href="style.css" rel="stylesheet" type="text/css" />
</head>

<body>
<div class="main">

<%@ include file="header.html" %>
<div id="left">
<div class="left_text">
<div class="title_left">
<font color="brown"> </font>
</div>
<p>
<f:view>

<h:form id="form1" >
First Name :
<h:inputText id ="fullName" value="#{dbBean.fullName}"/><BR>
email :
<h:inputText id ="email" value="#{dbBean.email}"/><BR>
password :
<h:inputSecret id ="password" value="#{dbBean.password}"/><BR>
job :
<h:inputText id ="job" value="#{dbBean.job}"/><BR>

<h:commandButton value="Register" action="#{dbBean.addUser}"/>
</h:form>
</f:view>

</p>

</div>
</div>

<jsp:include flush="true" page="links.jsp"/>

<div id="bottom">
<div style="background-color:#333333;">
<div class="bottom">
<div class="title">
<font color="brown"> Lorem ipsum </font>
</div>
<div class="text_bottom">
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aliquam
at libero. Suspendisse non risus a diam convallis
<a href="#">lobortis</a>.
</div>
</div>
</div>
</div>

<%@ include file="footer.html" %>

</div>
</body>
</html>

------------------------------------------------------------------------
addUser()

public String addUser()
{
UserBean bean = new UserBean();

ExternalContext context =
FacesContext.getCurrentInstance().getExternalContext();
HttpServletRequest request =
(HttpServletRequest)context.getRequest();

String fullName = request.getParameter("form1:fullName");
bean.setFullName(fullName);

String email = request.getParameter("form1:email");
bean.setEmail(email);

String password = request.getParameter("form1:password");
bean.setPassword(password);

String job = request.getParameter("form1:job");
bean.setJob(job);

try {
Connection Conn = DBManager.getConnection();
Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE ,ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stmt.executeQuery("select * from user");

rs.moveToInsertRow();
rs.updateString(1, bean.getFullName());

System.out.println("name"+ bean.getFullName());
rs.updateString(2, bean.getEmail());

rs.updateString(3, bean.getPassword());

rs.updateString(4,bean.getJob());

rs.insertRow();

rs.first();

}

catch (SQLException ex)
{
ex.printStackTrace();
return "failed";
}

return "sucsess" ;
}
Thanks in advance
Zohreh