Just fix your HTML, no body tags and some styling:
<script type="text/javascript">
function doSubmit(){
}
function closeThis(caller){
$(caller).closest('.ui-dialog').children('.ui-dialog-content').dialog('close');
return false;
}
</script>
<div style="width:100%;height:100%">
<form id="form1" runat="server" style="display:block;">
<p>Hello</p>
<iframe id="iframeCV" runat="server" width="100%" height="100%" style="border:0;width:100%;height:100%"></iframe>
<button onclick="doSubmit();">Submit</button>
<button onclick="closeThis(this);">Cancel</button>
</form>
</div>