function externalLinks() {
	if (!document.getElementsByTagName) return;
	var anchors = document.getElementsByTagName("a");
		
	for (var i=0; i < anchors.length; i++) {
		var anchor = anchors[i];
				
		if (anchor.getAttribute("href") &&
   		anchor.getAttribute("rel") == "external")
 		anchor.target = "_blank";
			}
		}
			
window.onload = externalLinks;