function external_links()
{
	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';
	}
}

function showHeader(header) {
	if(header == '' || header == 0)
		return;
	else
		document.getElementById("header").style.backgroundImage = 'url("images/headers/'+header+'")';
}