function disable_external_urls() {
	//roll over the DOM and sort out links not to this site.
	var localhref = window.location.protocol +"//"+ window.location.host;
	var anchors = document.getElementsByTagName("a");
	var i;
	var targ;

	for (i=0; i<anchors.length; i++) {
		targ = anchors[i].href
		if(targ.match("javascript:") == null && targ.match(localhref) == null) {
			//anchors[i].href = "#";
			anchors[i].href = "../external_link";
			anchors[i].target = "_self";
		}

	}
}