jquery form validation

jquery form validation

Hi to all
In my page i want to do form validation and the following are the part of my code but its not working
<html><head>
   <link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" rel="stylesheet" type="text/css"/>
  <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>
  <script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<style>#docs {
    display: block;
    position: fixed;
    bottom: 0;
    right: 0;
}</style>

<script>$(document).ready(function () {

    $('#myform').validate({ // initialize the plugin
        rules: {
            field1: {
                required: true,
                email: true
            },
            field2: {
                required: true,
                minlength: 5
            }
        },
        submitHandler: function (form) { // for demo
            alert('valid form submitted'); // for demo
            return false; // for demo
        }
    });

});</script>
</head><body><form id="myform">
    <input type="text" name="field1" />
    <br/>
    <input type="text" name="field2" />
    <br/>
    <input type="submit" />
</form>
<a id="docs" href="http://docs.jquery.com/Plugins/Validation" target="_blank">Validation Documentation</a></body></html>

can anybody please tell me where i have made mistake