function externalLinks() 
{
	if (!document.getElementsByTagName) return;
	var anchors = document.getElementsByTagName("a");
	var yourURL = "dbtuna.com";
	for (var i=0; i<anchors.length; i++) {
		var anchor = anchors[i];
		if (
			anchor.getAttribute("href") && ( 
			anchor.href.indexOf(yourURL) == -1 )
		)
		anchor.target = "_blank";
	}
}

externalLinks();