if( navigator.userAgent.indexOf('MSIE')!=-1 ){
    window.attachEvent('onload', loadExternalUrl );
}		
if( navigator.userAgent.indexOf('Gecko')!=-1 ){
    window.addEventListener( 'load', loadExternalUrl, false );
}
function loadExternalUrl(){
	if( !document.getElementsByTagName ){
        return;
    }
	var links=document.getElementsByTagName( 'a' );
	for( var i=0; i<links.length; i++ ){
		if( links[i].rel=="external" ){
			links[i].target="_blank";
		}
	}
}