$(document).ready(function() {
    $("a[@rel='external']").addClass("external").click(function() {
		window.open($(this).href());
		return false;
	})
	
	$("a[@rel='popup']").addClass("popup").click(function() {
		var ample = 500;
		var alt = 400;
		var x = (screen.availWidth - ample)/2;
		var y = (screen.availHeight - alt)/2;		
		window.open($(this).href(), $(this).title(), "width = " + ample + ", height = " + alt + ", left = " + x + ", top = " + y + ", scrollbars = yes, menubar = yes, toolbar = no, location = yes, directories = no, resizable = yes");
		return false; 
	})
});