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";
	 }
}
document.observe('dom:loaded', function(){
	try {
	  document.execCommand('BackgroundImageCache', false, true);
	} catch(e) {}
	externalLinks();
});