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";
 }
}
externalLinks(); window.onload = externalLinks;

function changeSrc(img, src) {
	document.getElementById(img).src=src;
}