function externalLinks(){
    var hostname = window.location.hostname;
    hostname = hostname.replace("www.","").toLowerCase();
    var a = document.getElementsByTagName("a"); 
    this.check = function(obj){
        var href = obj.href.toLowerCase();
        return (href.indexOf("http://")!=-1 && href.indexOf(hostname)==-1) ? true : false;              
    };
    this.set = function(obj){
        obj.target = "_blank";
        obj.className += " external";
            if (!obj.title) {
                obj.title = "Open link in new window";
            }
    };  
    for (var i=0;i<a.length;i++){
        if(check(a[i])) set(a[i]);
    };      
};

window.onload = externalLinks;