function Over(ImgId){
	thisImg = document.images[ImgId].src;
	newImg = thisImg.replace(".gif","_o.gif");
	document.images[ImgId].src = newImg;
	
}

function Out(ImgId){
	thisImg = document.images[ImgId].src;
	newImg = thisImg.replace("_o.gif",".gif");
	document.images[ImgId].src = newImg;
}