function links_target () {
	var elements = document.getElementsByTagName('a');
	for(i in elements){
		var thiselem = elements[i];
		var relval = thiselem.rel;
		if(relval == 'external'){
			thiselem.onclick = function(){
				var thishref = this.href;
				if(window.open(thishref) != null)
					return false;
			}
		}
	}
}

window.onload = function(){
	links_target();
}