Hi,
<script type="text/javascript">
<!--
function los()
{
if (what_to_do == 0)
if (formular.whatto_do.value == 0)
document.formular.submit();
}
//-->
</script>
...
<form name="formular" action="action.php3" method="post">
...
<select name="what_to_do">
<option value="0">neuer Eintrag
<option value="1">Eintrag suchen
<option value="2">Eintrag killen
</select>