DropdownList using razor in MVC 3

<script type="text/javascript">
    $(document).ready(function () {



        $("#CountryID").change(function () {
//            alert("Hi");
            var url = '@Url.Content("~/")' + "UserInfo/BindCity";
            var ddlSource = "#CountryID";
            var ddlTarget = "#Cities";

            $.getJSON(url, { c: $(ddlSource).val() }, function (data) {
                $(ddlTarget).empty();
                $.each(data, function (index, optionData) {
                    $(ddlTarget).append("<option value='" + optionData.Value + "'>" + optionData.Text + "</option>");
                });
            });
        });
    });

</script>

   <td>
                    <div class="editor-label">
                        @Html.Label("Country")
                    </div>
                    <div class="editor-field">
                        @Html.DropDownList("CountryID", (IEnumerable<SelectListItem>)ViewData["Ct"],
new { id = "CountryID" })
                        <br />
                        @* @Html.ValidationMessageFor(model => model.ContactNo)*@
                    </div>
                    <div class="editor-label">
                        @Html.Label("City")
                    </div>
                    <div class="editor-field">
                        @Html.DropDownList("Cities")
                    </div>
                </td>