Need som help with lightface

[Fenhopi]

Hi, I use a script called lightface to bring up a facebook like popon box on my site.

 

window.addEvent('domready',function(){

		document.id('sup').addEvent('click',function() {

			light = new LightFace.IFrame({ height:350, width:640, url: 'editContact.php?user=<? echo $username; ?>', title: 'Edit Contact information!' }).addButton('Close', function() { light.close(); },true).open();

		});

	});

 

That's the code I use to load a page in lightface, however I want to create it so that it can retrieve a php value into the site I open in lightface. In my case I'm trying to load a post id. Does anyone have any suggestions how I'd go about doing that?