function externalLinks() {
	if (!document.getElementsByTagName) return;	// Netscape 4 and IE4 don't support DOM1
	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;	// assigns the externalLinks function to the window's onload event handler.
					// This triggers the function when the document has finished loading.
					// Source : http://www.sitepoint.com/article/standards-compliant-world