I'm having the "Microsoft JScript runtime error: Object doesn't support this property or method" error when calling the datepicker function on a textbox generated from my data model.

in the head section I have:

<link href="../../Content/Site.css" rel="stylesheet" type="text/css" />
<script src="../../Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
<script src="../../Scripts/MicrosoftAjax.js" type="text/javascript"></script>
<script src="../../Scripts/MicrosoftMvcValidation.js" type="text/javascript"></script>

<script type="text/javascript">
    $(document).ready(function () {
        $('#dob').datepicker();
    });

and in the body section I have:

<% Html.EnableClientValidation(); %>
<% using (Html.BeginForm()) { %>

...

<tr>
    <td class="label">Date of Birth:</td>
    <td><%: Html.TextBoxFor(model => model.dob, new { @class = "inputtext" })%></td>
    <td><%: Html.ValidationMessageFor(model => model.dob) %></td>
</tr>

...

<% } %>

Do I have something in the wrong place?

Again, you folks are a great help and assistance would be greatly appreciated.