<script type="text/javascript" language="javascript" src="http://www.1sucai.cn/Scripts/jquery-1.4.1.min.js"></script>
<script type="text/javascript" language="javascript" src="http://www.1sucai.cn/Scripts/jquery.validate.min.js"></script>
<script type="text/javascript" language="javascript" src="http://www.1sucai.cn/Scripts/jquery.form.js"></script>
<h2>
  AjaxFrom</h2>
<div id="output1" style="color: Red;">
</div>
<%using (Html.BeginForm("Login", "Home", FormMethod.Post, new { id = "loginForm" }))
 { %>
<table border="0" cellpadding="0" cellspacing="0">
  <tr>
    <td>
      <%=Html.TextBox("UserEmail", "", new { @class="name required"})%>
    </td>
  </tr>
  <tr>
    <td>
      <%=Html.Password("Password", "", new { @class = "required" })%>
    </td>
  </tr>
  <tr>
    <td>
      <input type="submit" value="submit" />
    </td>
  </tr>
</table>
<%} %>
<script language="javascript" type="text/javascript">

  $(document).ready(function () {
    var opts = {

      submitHandler: function (form) {
        var submitOpts = {
          target: '#output1',
          success: function () {
            alert('Thanks for your comment!');
          }
        };
        $(form).ajaxSubmit(submitOpts);
      }

    };
    jQuery("#loginForm").validate(opts);
  });  
</script>

public PartialViewResult Login(string UserEmail, string Password)
{

  // you code
  return PartialView("Success");
}