una cosa così?

codice:
<script language="javascript1.2" type="text/javascript"> 

function aggiorna(f,a) 
{ 
f.target="_self"; 
f.action=a; 
f.submit(); 
} 
</script> 

<form action="" name="xx"> 
<select name="dd" onchange="aggiorna(this.form, 'paginaaction.php')"> 
<option value="1">1</option> 
<option value="2">2</option> 
<option value="3">3</option> 
</select> 

</form>
fammi sapere! ;)