function secImg(id,h,w,defImg){
	this.id=id;
	this.h=h;
	this.w=w;
	this.secs=new Array()
	this.imgName=this.id+'_img'
	document.write('<img name="'+this.imgName+'" id="'+this.imgName+'" src="'+defImg+'" width="'+this.w+'" height="'+this.h+'" border="1">')
}
secImg.prototype.add=function(id,src){
	this.secs[id]=new Image();
	this.secs[id].src=src;
}
secImg.prototype.swap=function(id){
	getElem(this.imgName).src=this.secs[id].src;
}