window.onload = externalLinks;

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.onclick = function() {
extPop(this.href);
return false;
};
}
}

function extPop(url) {
newWin = window.open(url,"_blank","top=0,left=0,height=500,width=700,channelmode=0,dependent=0,directories=1,fullscreen=0,location=1,menubar=1,resizable=1,scrollbars=1,status=1,toolbar=1");
}