Added this line in the script tag and it works:  $("#dialog").parent().appendTo($("form:first"));

1.         <script type="text/javascript"> 
2.             $(document).ready(function () {
3.                 $("#dialog").dialog({
4.                     autoOpen: true,
5.                     modal: true,
6.                     draggable: false,
7.                     resizable: false
8.                 });
9.                 $("#open").click(function () {
10.                     $("#dialog").dialog("open");
11.                 });
12.               $("#dialog").parent().appendTo($("form:first"));
13.             });
14.         </script> 

Thank you,

Xmas79.

P.S.

At the right bottom of this editor here in the forum I have a wrong translation on chars count. Let me know who I can contact to correct this translation.