/* Simple Layer library with very basic compatability checking */
var layerobject;
var allobject;
var dom;
var opera;
/* detect objects */
(document.layers) ? layerobject = true : layerobject = false;
(document.all) ? allobject = true: allobject = false;
(document.getElementById) ? dom = true : dom = false;

/* detect browsers */
opera=navigator.userAgent.toLowerCase().indexOf('opera')!=-1;

/* return the object for the passed layerName value */
function getElement(layerName,parentLayer) 
{
 if (layerobject)
  {
    parentLayer = (parentLayer)? parentLayer : self;
	layerCollection = parentLayer.document.layers;
	if (layerCollection[layerName])
	  return layerCollection[layerName];
	
	/* look through nested layers */
	for(i=0; i < layerCollection.length;)
	  return(getElement(layerName, layerCollection[i++]));
   }
	
  if (allobject)
    return document.all[layerName];

  if (dom)
    return document.getElementById(layerName); 
} 

/* hide the layer with id = layerName */
function hide(layerName)
 {
   var theLayer = getElement(layerName);
   
   if (layerobject)
     theLayer.visibility = 'hide';
   else
     theLayer.style.visibility = 'hidden';
  }


/* show the layer with id = layerName */
function show(layerName)
 {
   var theLayer = getElement(layerName);
   
   if (layerobject)
     theLayer.visibility = 'show';
   else
     theLayer.style.visibility = 'visible';
  }


/* set the x-coordinate of layer named layerName */
function setX(layerName,x) 
 {
   var theLayer = getElement(layerName);
   
   if (layerobject)
     theLayer.left=x;
   else  
     theLayer.style.left=x+"px";
 } 

/* set the y-coordinate of layer named layerName */
function setY(layerName, y) 
 {
   var theLayer = getElement(layerName);

   if (layerobject)
     theLayer.top=y;
   else  
     theLayer.style.top=y+"px";
 }

/* set the z-index of layer named layerName */
function setZ(layerName, zIndex) 
 {
   var theLayer = getElement(layerName);

   if (layerobject)
     theLayer.zIndex = zIndex;
   else
     theLayer.style.zIndex = zIndex;
 } 

/* set the height of layer named layerName */
function setHeight(layerName, height) 
 {
   var theLayer = getElement(layerName);

   if (layerobject)
     theLayer.clip.height = height;
   else if (opera)
     theLayer.style.pixelHeight = height;
   else
     theLayer.style.height = height;
 }

/* set the width of layer named layerName */
function setWidth(layerName, width) 
 {
  var theLayer = getElement(layerName);

   if (layerobject)
     theLayer.clip.width = width;
  else if (opera)
     theLayer.style.pixelWidth = width;
   else
     theLayer.style.width = width;
 }

/* set the a clipping rectangle on the layer named layerName
   defined by top, right, bottom, and left */
function setClip(layerName, top, right, bottom, left) 
 {
 
   var theLayer = getElement(layerName);
 
   if (layerobject)
     {
	   theLayer.clip.top = top;
	   theLayer.clip.right = right;
	   theLayer.clip.bottom = bottom;
	   theLayer.clip.left = left;
	  }
	else
	  theLayer.style.clip = "rect("+top+" "+right+" "+" "+bottom+" "+left+")";
 }
 

/* set the contents of layerName to passed content*/
function setContents(layerName, content)
 {
   var theLayer = getElement(layerName);

   if (layerobject)
     {
	  theLayer.document.write(content);
	  theLayer.document.close();
	  return;
	 }
	 
   if (theLayer.innerHTML)
     theLayer.innerHTML = content;
 }