Untitled

function preview_enhanced(event)
        {
            var b = $("#enhanced_listing_modal").val();
            var content = $.parseHTML(b);

            $("#enhanced_listing_modal").html(content).dialog({
                width: 900,
                height: 600,
                modal: true,
                buttons: {
                    "Close Preview": function() {
                        $(this).dialog("close");
                    }
                }

            });
        }

$("#enhanced_listing_modal").val();

$("#enhanced_listing_modal").html(content).dialog({
to
$("#enhanced_listing_modal").dialog({

<html>
  <header><title>This is title</title></header>
  <body>
     Hello world
  </body>
</html>