var timerlen = 5;
var slideAniLen = 500;

var timerID = new Array();
var startTime = new Array();
var obj = new Array();
var endHeight = new Array();
var moving = new Array();
var dir = new Array();

function slidedown(objname){
  if(moving[objname])
    return;
 
  if(document.getElementById(objname).style.display != "none")
    return; // cannot slide down something that is already visible
 
  moving[objname] = true;
  dir[objname] = "down";
  startslide(objname);
}
 
function slideup(objname){
  if(moving[objname])
    return;
 
  if(document.getElementById(objname).style.display == "none")
    return; // cannot slide up something that is already hidden
 
  moving[objname] = true;
  dir[objname] = "up";
  startslide(objname);
}

function startslide(objname){
  obj[objname] = document.getElementById(objname);
 
  endHeight[objname] = parseInt(obj[objname].style.height);
  startTime[objname] = (new Date()).getTime();
 
  if(dir[objname] == "down"){
    obj[objname].style.height = "1px";
  }
 
  obj[objname].style.display = "block";
 
  timerID[objname] = setInterval('slidetick(\'' + objname + '\');',timerlen);
}

function slidetick(objname){
  var elapsed = (new Date()).getTime() - startTime[objname];
 
  if (elapsed > slideAniLen)
    endSlide(objname)
  else {
    var d =Math.round(elapsed / slideAniLen * endHeight[objname]);
    if(dir[objname] == "up")
      d = endHeight[objname] - d;
 
    obj[objname].style.height = d + "px";
  }
 
  return;
}

function endSlide(objname){
  clearInterval(timerID[objname]);
 
  if(dir[objname] == "up")
    obj[objname].style.display = "none";
 
  obj[objname].style.height = endHeight[objname] + "px";
 
  delete(moving[objname]);
  delete(timerID[objname]);
  delete(startTime[objname]);
  delete(endHeight[objname]);
  delete(obj[objname]);
  delete(dir[objname]);
 
  return;
}

function toggleLayer( whichLayer )
{
  var elem, vis;
  if( document.getElementById ) // this is the way the standards work
    elem = document.getElementById( whichLayer );
  else if( document.all ) // this is the way old msie versions work
      elem = document.all[whichLayer];
  else if( document.layers ) // this is the way nn4 works
    elem = document.layers[whichLayer];
  vis = elem.style;
  // if the style.display value is blank we try to figure it out here
  if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)
    vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';
  vis.display = (vis.display==''||vis.display=='block')?'none':'block';
}

function showLayer(id) {
layer = browser(id)
   if(nn4){
   layer.visibility = "visible"
   }
   else{
   layer.style.visibility = "visible"
   }
}

function hideLayer(id) {
layer = browser(id)
   if(nn4){
   layer.visibility = "hidden"
   }
   else{
   layer.style.visibility = "hidden"
   }
}

function toggleSlide(objname){
  if(document.getElementById(objname).style.display == "none"){
    // div is hidden, so let's slide down
    slidedown(objname);
  }else{
    // div is not hidden, so slide up
    slideup(objname);
  }
}

function toggleAll(id) {
	if (id == 'submenuBio') {
		toggleVisibility('submenuSchedule');
		toggleVisibility('submenuResources');
		toggleVisibility('submenuContact');
		toggleVisibility('submenuLinks');
	}
	if (id == 'submenuSchedule') {
		toggleVisibility('submenuBio');
		toggleVisibility('submenuResources');
		toggleVisibility('submenuContact');
		toggleVisibility('submenuLinks');
	}
	if (id == 'submenuResources') {
		toggleVisibility('submenuBio');
		toggleVisibility('submenuSchedule');
		toggleVisibility('submenuContact');
		toggleVisibility('submenuLinks');
	}
	if (id == 'submenuContact') {
		toggleVisibility('submenuBio');
		toggleVisibility('submenuSchedule');
		toggleVisibility('submenuResources');
		toggleVisibility('submenuLinks');
	}
	if (id == 'submenuLinks') {
		toggleVisibility('submenuBio');
		toggleVisibility('submenuSchedule');
		toggleVisibility('submenuResources');
		toggleVisibility('submenuContact');
	}
	
	toggleLayer(id);
}

function toggleVisibility(id) {
   var e = document.getElementById(id);
   e.style.display = 'none';
}