function fn_event (obj_object, str_event, str_function) {

	if (obj_object.addEventListener) {
   		obj_object.addEventListener(str_event, str_function, true);
   		return true;
	}

	else if (obj_object.attachEvent) {
		return obj_object.attachEvent("on" + str_event, str_function);
	}

	else {
		return false;
	}
}

function fn_ahref() {

	if (!document.getElementsByTagName) return;
	arr_nodes = document.getElementsByTagName('A');

	for (i = 0; i < arr_nodes.length; i++) {
		obj_node = arr_nodes[i];
		if (obj_node.getAttribute('href') && obj_node.getAttribute('rel') == 'external')
		obj_node.target = '_blank';
	}
}

fn_event (window, 'load', fn_ahref);