function change_highlight(hl_title, hl_link, hl_img) {
	highlight_image_html = "<a href='"+hl_link+"'><img src='"+hl_img+"' width='618' height='425' alt='"+hl_title+"' /></a>";
	highlight_title_html = "<h3><a href='"+hl_link+"'>"+hl_title+"</a></h3>";
	document.getElementById('highlight_image').innerHTML = highlight_image_html;
	document.getElementById('highlight_title').innerHTML = highlight_title_html;
}

function showLayer(layer_id) {
	if (document.getElementById(layer_id)) {
		if (document.getElementById(layer_id).style.display == '') {
			document.getElementById(layer_id).style.display = 'none'
		} else {
			document.getElementById(layer_id).style.display = ''
		}
	}
}