<img src="my.jpg" width=200px onmouseover=f1(0) onmouseout=f2()>
<script type="text/JavaScript">
function f1(z)
{
document.images[0].src=document.images[z].src;
document.images[1].src=document.images[z].src;
document.images[2].src=document.images[z].src;
document.images[z].style.width="210px";
document.images[z].style.transition="500ms";

}
function f2()
{
document.images[0].src="my.jpg";
for(var i=0;i<=2;i++)
document.images[i].style.width="200px";
document.images[i].style.transition="500ms";
}
</script>