nn è difficile ... basta giocare un po cn le proprietà dell'oggetto che vuoi modificare:
codice:
<script>
function aumentaDim(idElementoDaModificare, width)
{
var el=document.getElementById(idElementoDaModificare);
var nL=parseInt(el.style.width);
if(width>nL)
{
var w=width-nL;
}else
{
var w=nL-width;
}
var u=w/10;
var myw=width+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",100);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",200);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",300);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",400);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",500);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",600);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",700);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",800);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",900);
myw=myw+u
window.setTimeout("document.getElementById('"+el.id+"').style.width='"+myw+"px'",1000);
}
</script>
<div id="prova" style="border:1px solid #000000; width:50px; height:30px;'" onmouseover="aumentaDim(this.id, 100)"></div>