quindi suppongo che sia una cosa del genere...

<script>
function doSomething(e)
{
var targ;
if (!e) var e = window.event;
if (e.target) targ = e.target;
else if (e.srcElement) targ = e.srcElement;
alert(targ.name);
}
</script>
<form onclick="doSomething()">
<input name="i1">

<input name="i2">

<input name="i3">

<input name="i4">

</form>