<form name="f">
<input type=TEXT><input type=TEXT>
<input type=button value="Change Focus" onclick="ChngFocus();">
</form>
<script language="JavaScript">
<!--
var cnt=0;
document.f.elements[0].focus();
function ChngFocus(){
document.f.elements[cnt].blur();
document.f.elements[cnt^1].focus();
cnt ^= 1;
}
//-->
</script>