I am trying to open the JQueryUI Modal Form with the text box and the button. It opened the form but I cannot access it. If I use the modal:false, I can access not only the form but also the items on the page. I want the modal one and restrict the access to underlying form items.

My Javascript code is as follow:
<script language="javascript" type="text/javascript">
$().ready(function () {
CreateDialog();
$("#hlTest").click(function () {
$("#dvDialog").dialog("open");
});
});
function CreateDialog() {
$("#dvDialog").dialog({
autoOpen: false,
height: 280,
width: 440,
modal: true,
open: function () {
$(this).parent().appendTo($("form:first"));
}
});
}
</script>
My ASP.Net Form codes are as follow:
<a href="#" id="hlTest">Test</a>
<div id="dvDialog" title="Comment">
<b>Comment: </b>
<asp:TextBox ID="txtComment" runat="server" TextMode="MultiLine" Rows="4" Columns="50" ValidationGroup="vDialog"></asp:TextBox>
<br />
<asp:Button ID="btnSaveComment" runat="server" Text="Save" ValidationGroup="vDialog" OnClick="btnSaveComment_Click" />
</div>