function externalLinks() {
 	for (i = 0; i < document.links.length; i++) {
		var link = document.links[i];
		if (link.getAttribute('href') && link.getAttribute('rel') == 'external') {
			link.target = '_blank';
		}
	}
}

window.onload = function() {
	externalLinks();
}

function popup(url) {
	var width  = 800;
	var height = 450;
	var left   = (screen.width  - width)/2;
	var top    = (screen.height - height)/2;
	var params = 'width='+width+', height='+height;
	params += ', top='+top+', left='+left;
	params += ', directories=no';
	params += ', location=no';
	params += ', menubar=no';
	params += ', resizable=no';
	params += ', scrollbars=no';
	params += ', status=no';
	params += ', toolbar=no';
	newwin=window.open(url,'windowname5', params);
	if (window.focus) {newwin.focus()}
	return false;
}