JQuery Validate Plugin MS MVC: Won't validate

I'm trying out the jQuery Validation plugin jQuery Docs Here is the markup of my form:

<% using (Html.BeginForm("action", "contoller", null, FormMethod.Post, new { id = "sxform" })){%>

    <div id="manifest">
        Manifest Option:<br />
        <%= Html.DropDownList("docid", ViewData["manifests"] as SelectList, new { @class = "required" })%&开发者_JS百科gt;
    </div>
    <div id="release">
        Release Version:<br />
        <%= Html.TextBox("release", null, new { @class = "required" })%>
    </div>
    <div id="locale">
        Localization:<br />
        <%= Html.DropDownList("localization", ViewData["localizations"] as SelectList, new { @class = "required" })%>
    </div>
    <div id="label">
        Label:<br />
        <%= Html.TextBox("label", null, new { @class = "required" })%>
    </div>
    <div id="session">
        Session ID (optional):<br />
        <%= Html.TextBox("sessionInput", null, new { @class = "required" })%>
    </div>
    <div id="submit"><input type="submit" value="Build" /></div>    

<% } %>

JS:

$(document).ready(function(){
    $("#sxform").validate();
});

I am using MS MVC HTML Helpers to render this form. The resulting markup looks fine. IE each input and selection element contains the attribute 'class' with the value 'required'.

When I submit this form the validation does noting. Can someone familiar with this library help? It looks pretty widely used.

Thanks!

You code looks fine and should work. Make sure you have included the plugin:

<script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/validate/jquery.validate.js"></script>

Also look for possible javascript errors in the FireBug console.