/**
 * @author Jeroen
 */
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";
    }
}

window.onload = externalLinks;