function toggleLayer(whichLayer)
{
if (document.getElementById)
{ // this is the way the standards work
var style2 = document.getElementById(whichLayer).style;
style2.display = style2.display? "":"block"; }
else if (document.all)
{// this is the way old msie versions work
var style2 = document.all[whichLayer].style;
style2.display = style2.display? "":"block"; }
else if (document.layers)
{// this is the way nn4 works
var style2 = document.layers[whichLayer].style;
style2.display = style2.display? "":"block"; }
}
//These are the ids for the intial active menu button and div
var currentlayer = "index";
var currentmenu = "indexLink";

function changeclass(id, newClass) {
identity=document.getElementById(id);
identity.className=newClass; }

function showLayer(newlayer, newmenu)
{ 
 if(currentlayer != newlayer)
 { toggleLayer(currentlayer);
   toggleLayer(newlayer);  
   changeclass(currentmenu, "menuoff");
   changeclass(newmenu, "menuon");
   currentlayer = newlayer;    
   currentmenu = newmenu;
 }
}