function setTitle(titlename) {
	document.title = titlename;
}

function setBackgroundColor(colorname) {
	document.bgColor = colorname;
}

function showLayer(element_id) {
	if (  
		document.getElementById && 
		document.getElementById(element_id) &&
		document.getElementById(element_id).style
      )
	{
		document.getElementById(element_id).style.visibility="visible";
		document.getElementById(element_id).style.display="inline";	
	}
}

function hideLayer(element_id) {
	if (  
		document.getElementById && 
		document.getElementById(element_id) &&
		document.getElementById(element_id).style
      )
   {
		document.getElementById(activeLayer).style.visibility="hidden";
		document.getElementById(activeLayer).style.display="none";
		activeLayer = element_id;
   };
}