function external() {
 	var formular = document.getElementById("link2map24");
    formular.target = "_blank";
	
	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";
		}
	}
}

Event.observe(window, 'load', external, false);