/*
 ImgRollerSet
*/

function ImgRollerSet(stub, onIns, offIns)
/*
 stub: to be prepended to img file names inclue trailing /
 onIns: inserted to the name for the 'on' img
 offIns: inserted to the name for the 'off' img
*/
{ 
  if(stub != null)
  {
    this.imgs = new Object();
    this.stub = stub;
    this.onIns = onIns;
    this.offIns = offIns;
    this.onrollon = null;
    this.onrolloff = null;
  }
}
new ImgRollerSet(null, null, null);


function ImgRollerSet_add(baseName, ext, jsImgName)
/*
 ext: no . needed
*/
{
  this.imgs[jsImgName] = new Object();
  
  this.imgs[jsImgName].jsImgName = jsImgName;
  this.imgs[jsImgName].parent = this;
  
  this.imgs[jsImgName].off = new Image();
  this.imgs[jsImgName].off.src = 
   (this.stub + baseName + this.offIns + "." + ext);

  this.imgs[jsImgName].on = new Image();
  this.imgs[jsImgName].on.src = 
   (this.stub + baseName + this.onIns + "." + ext);  
}
ImgRollerSet.prototype.add = ImgRollerSet_add;


function ImgRollerSet_set()
{
  var docImgs = document.images;
  var docLnks = document.links;
  
  var i, name, obj;
  
  for(i = 0; i < docImgs.length; i++)
  {
    if(this.imgs[docImgs[i].name] != null)
    {
      this.imgs[docImgs[i].name].docImg = docImgs[i];
    }
  }
  
  for(i = 0; i < docLnks.length; i++)
  {
    if(docLnks[i].onmouseover != null)
    {
      if((obj = docLnks[i].onmouseover()) != null)
      {
        if((name = obj.name) != null)
        {
          if(this.imgs[name] != null)
          {
            docLnks[i].imgRoller = this.imgs[name];
            docLnks[i].onmouseover = ImgRoller_on;
            docLnks[i].onmouseout = ImgRoller_off;
          }
        }
      }
    }
  }
}
ImgRollerSet.prototype.set = ImgRollerSet_set;

function ImgRoller_on()
{ 
  var roller = this.imgRoller;

  roller.docImg.src = roller.on.src;

  if(roller.parent.onrollon != null)
  {
    roller.parent.onrollon();
  }
}


function ImgRoller_off()
{
  var roller = this.imgRoller;

  roller.docImg.src = roller.off.src;
  
  if(roller.parent.onrolloff != null)
  {
    roller.parent.onrolloff();
  }
}