var page = "http://somurl.com/asom.php.aspx";
var $dialog = $('<div></div>')
.html('<iframe style="border: 0px; " src="' + page + '" width="100%" height="100%"></iframe>')
.dialog({
autoOpen: false,
modal: true,
height: 625,
width: 500,
title: "Some title"
});
$dialog.dialog('open');
Use this inside a function. This is great if you really want to load an external URL as an IFRAME. Also make sure that in you custom jqueryUI you have the dialog.