function RolloverEngine(pat)
{if(pat && pat != null)
this.pattern = (typeof pat == "string") ? new RegExp(pat) : pat;
else this.pattern = null;

RolloverEngine.images = new ImageCollection();
this.ready = false;
this.findImages();
this.ready = true;

return this;
}

RolloverEngine.prototype.findImages = function(doc)
{if(!doc) doc = window.document;

if(doc.images.length > 0)
{var img, a, b;
for(a = 0; a < doc.images.length; a++)
{img = doc.images[a];
if ((img != null) && (img.name))
if(this.pattern == null || this.pattern.test(img.name))
this.loadImage(img);

}
}
if(doc.layers && doc.layers != null)
{if(doc.layers.length > 0)
{for(b = 0; b < doc.layers.length; b++)
{this.findImages(doc.layers[b].document);
}
}
}
}

RolloverEngine.prototype.loadImage = function(img)
{if(img && img != null && img.src)
{lastSlash = img.src.lastIndexOf("/");
if(lastSlash == -1) lastSlash = 0;

lastDot = img.src.lastIndexOf(".");
if(lastDot == -1) lastDot = img.src.length;

imgLoc = (lastSlash > 0) ? img.src.substring(0, lastSlash + 1) : new String("");
baseName = img.src.substring(lastSlash + 1, lastDot);
ext = img.src.substring(lastDot, img.src.length);

// fix for old _off naming
offIndex = baseName.lastIndexOf("_off");
if(offIndex != -1) baseName = baseName.substring(0, offIndex);

img.off = new Image();
img.off.src = img.src;
img.over = new Image();
img.over.src = imgLoc + baseName + "_over" + ext;
img.on = new Image();
img.on.src = imgLoc + baseName + "_on" + ext;

RolloverEngine.images.addImage(img);
}
}

RolloverEngine.prototype.containsImage = function(strName)
{return (strName && strName != null) ? (RolloverEngine.images[strName] && RolloverEngine.images[strName] != null) : false;
}

RolloverEngine.prototype.getImage = function(strName)
{return (this.containsImage(strName)) ? RolloverEngine.images[strName] : null;
}

RolloverEngine.prototype.setOff = function(strName)
{img = this.getImage(strName);
if(img && img != null && this.ready && !img.locked) img.src = img.off.src;
}

RolloverEngine.prototype.setOver = function(strName)
{img = this.getImage(strName);
if(img && img != null && this.ready && !img.locked) img.src = img.over.src;
}

RolloverEngine.prototype.setOn = function(strName)
{img = this.getImage(strName);
if(img && img != null && this.ready && !img.locked) img.src = img.on.src;
}

RolloverEngine.prototype.setAllOff = function()
{if(this.ready)
{for(a = 0; a < RolloverEngine.images.countImages(); a++)
{img = RolloverEngine.images.imageAt(a);
if(!img.locked) img.src = img.off.src;
}
}
}

RolloverEngine.prototype.isOff = function(strName)
{img = RolloverEngine.images[strName];
return (img && img != null && img.src == img.off.src);
}

RolloverEngine.prototype.isOver = function(strName)
{img = RolloverEngine.images[strName];
return (img && img != null && img.src == img.over.src);
}

RolloverEngine.prototype.isOn = function(strName)
{img = RolloverEngine.images[strName];
return (img && img != null && img.src == img.on.src);
}

RolloverEngine.prototype.lock = function(strName)
{img = RolloverEngine.images[strName];
if(img && img != null) img.locked = true;
}

RolloverEngine.prototype.lockAll = function()
{for(i = 0; i < RolloverEngine.images.countImages(); i++)
{RolloverEngine.images.imageAt(i).locked = true;
}
}

RolloverEngine.prototype.unlock = function(strName)
{img = RolloverEngine.images[strName];
if(img && img != null) img.locked = false;
}

RolloverEngine.prototype.unlockAll = function()
{for(j = 0; j < RolloverEngine.images.countImages(); j++)
{RolloverEngine.images.imageAt(j).locked = false;
}
}

RolloverEngine.prototype.isLocked = function(strName)
{img = RolloverEngine.images[strName];
return (img && img != null && img.locked && img.locked == true);
}

RolloverEngine.prototype.setSrc = function(strName, path)
{ img = this.getImage(strName);
 if(img && img != null && this.ready) img.src = path;
}

RolloverEngine.prototype.getSrc = function(strName)
{ img = this.getImage(strName);
 return img.src;
}

RolloverEngine.prototype.toString = function()
{return "[object RolloverEngine]";
}

function ImageCollection()
{this.images = new Array();
}

ImageCollection.prototype.addImage = function(img)
{if(img && img != null && img.name)
{this.images[this.images.length++] = img;
eval("this." + img.name + " = img;");
}
}

ImageCollection.prototype.imageAt = function(index)
{return (index >= 0 && index < this.images.length) ? this.images[index] : null;
}

ImageCollection.prototype.countImages = function()
{return this.images.length;
}

ImageCollection.prototype.toString = function()
{return "[object ImageCollection]";
}