function openExternal(){
	
    if(!document.getElementsByTagName) return;
    var anchors = document.getElementsByTagName("a");
    
	for(var i = 0; i < anchors.length; i++){
        var thisAnchor = anchors[i];
        if(thisAnchor.getAttribute("href") && thisAnchor.getAttribute("rel") == "blank"){
            thisAnchor.target = "_blank";
        }
    }
}


window.onload = openExternal;