Untitled

index.php:

<script type="text/javascript" src="js/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.4.custom.min.js"></script>

<script type="text/javascript">
function showRegDialog(url) {
	$(function() {


			var $this = $(this);
			var horizontalPadding = 30;
			var verticalPadding = 30;
			$('<iframe id="externalSite" scrolling="no" frameborder="0" class="externalSite" src="' + url + '" />').dialog({
				title: ($this.attr('title')) ? $this.attr('title') : 'Choose your location',
				autoOpen: true,
				width: 700,
				height: 700,
				modal: true,
				resizable: true,
				autoResize: true,
				overlay: {
					opacity: 0.5,
					background: "black"
				}

			}).width(700 - horizontalPadding).height(700 - verticalPadding);

	});
}
</script>
<script type="text/javascript">
function closeModal() {
    $("#externalSite").dialog("close");
}
</script>

iframe.php:

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script type="text/javascript" src="js/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.4.custom.min.js"></script>
<script>
$("#test2").submit(function(){
    parent.closeModal();
});
</script>
</head>

<body>

<form id="test2" action="" method="post">
<input type="submit" />
</form>

</body>
</html>