function external_blank(){
	if(!document.getElementsByTagName)return;
	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";
	}
}
window.onload=external_blank;