non riesco a far funzionare questa select box senza pulsante, deve puntare ad una pagina "result_receivers.asp"

codice:
<form method="post" action="result_receivers.asp" name="Receivers" onChange="location.href=result.Receivers.modulation.options[document.Receivers.modulation.selectedIndex].value;">
<select name="modulation" class="campiform">
<option selected>Select...</option>
<option value="All">All receivers</option>
<%do while not rs.EOF%>
<option value="<%=rs("modulation")%>"><%=rs("modulation")%></option>
<%rs.MoveNext
Loop%>
</select>
</form>