function ImageSwap(imgRef, period)
{
 this.period=period;
 this.timer=null;
 this.index=0;
 this.theElem=document.getElementById(imgRef);
 this.defSrc=this.theElem.src;
 this.imgData=[];
 
 for(var i=2,j=0; i<arguments.length; i++,j++)
 {this.imgData[j]=new Image();this.imgData[j].src=arguments[i];}
 
 this.trigElem = (this.theElem.parentNode.tagName=='A' ? this.theElem.parentNode : this.theElem);
 this.trigElem.onmouseout=this.trigElem.onblur=(function(obj){ return function()
 {clearInterval(obj.timer);obj.theElem.src=obj.defSrc;obj.index=0;}})(this);
 
 this.trigElem.onmouseover=this.trigElem.onfocus=(function(obj){return function()
 {obj.trigElem.onmouseout();obj.timer=setInterval((function(inst){return function(){inst.swap()}})(obj), obj.period);}})(this);
 this.swap=function(){if(this.index==this.imgData.length)this.index=0;this.theElem.src=this.imgData[ this.index++ ].src;}
}