Dealing with PressThis inside an administrative thickbox

press-this-thickbox.php

<?php
/**
  Auxiliary menu and page with a button to open the thickbox
 */
add_action('admin_menu', 'add_auxiliary_menu');

function add_auxiliary_menu() 
{
    add_menu_page(
        'TB', 
        '<span style="color:#e57300;">Thickbox</span>', 
        'edit_pages', 
        'thickbox-press-this', 
        'menu_page_content',
        '', // icon default for empty
        1  // create before Dashboard menu item
    );
}

function menu_page_content() 
{
	wp_enqueue_style('thickbox');
	wp_enqueue_script('thickbox');
	?>
	<div id="icon-post" class="icon32"></div>
	<h2>Press-This in a Thickbox</h2>

	<div style="width:50%; padding: 5px;" class="updated" >
	    <p><a class="button-secondary" href="#" id="open-tb"><?php _e( 'Press not this' ); ?></a></p>
	</div>
	<script type="text/javascript">
	jQuery(document).ready(function() {   
	    jQuery("#open-tb").click(function() {                 
	        tb_show("", "press-this.php?TB_iframe=true&width=720&height=570");
	        return false;
	    });
	});             
	</script>
	<?php
}


/**
 * Style and script for press-this.php
 */
add_action( 'admin_head', 'hide_press_this_notice' );
add_action( 'admin_footer', 'manipulate_press_this_notice' );

/**
 * Avoid visual glitches while manipulating with jQuery
 */
function hide_press_this_notice()
{
	?>
	<style>#message{opacity:0.01}</style>
	<?php
}

/**
 * The original Press This opens in a normal popup
 * ours, inside an iframe
 */
function manipulate_press_this_notice()
{
	// The actions of the file don't have a '-$hook'
	global $pagenow;
	if( 'press-this.php' != $pagenow )
		return;

	?>
	<script type="text/javascript"> 
		jQuery(document).ready(function($) 
		{ 
			// HAPPENING IN AN IFRAME
			if(top!=self)
			{
				$('#message a').last().remove();
				$('#message a').each( function() 
				{
					$(this).removeAttr('onclick');
					$(this).attr('target','_parent');
				});
			}
			// UNDO THE CSS RULE FOR BOTH
			$('#message').fadeTo(1500,1);
		});             
	</script>
	<?php
}