tI POSTO LA PAGINA COL TUO CODICE E IN + LA SELECT POPOLATA DAL db.

<%@LANGUAGE="VBSCRIPT"%>

<%
set Recordset1 = Server.CreateObject("ADODB.Recordset")
Recordset1.ActiveConnection = MM_Interventi_STRING
Recordset1.Source = "SELECT * FROM Anagrafica ORDER BY RagioneSociale ASC"
Recordset1.CursorType = 0
Recordset1.CursorLocation = 2
Recordset1.LockType = 3
Recordset1.Open()
Recordset1_numRows = 0
%>
<script>
function dennis(){
form=document.form1
valore=form.cerca.value
numero_caratteri=valore.length
lista=form.lista
for(i=0;i<lista.options.length;i++){
if(lista.options[i].text.substr(0,(numero_caratteri))==valore){
document.form1.lista.options[i].selected=true
break;
}
}
if(numero_caratteri==0){
document.form1.lista.options[0].selected=true
}
}
</script><form name="form1">
<input type="text" name="cerca" onKeyUp="dennis()">
<select name="lista">
<%
While (NOT Recordset1.EOF)
%>
<option value="<%=(Recordset1.Fields.Item("RagioneSociale" ).Value)%>" ><%=(Recordset1.Fields.Item("RagioneSociale").Valu e)%></option>
<%
Recordset1.MoveNext()
Wend
If (Recordset1.CursorType > 0) Then
Recordset1.MoveFirst
Else
Recordset1.Requery
End If
%>
</select>
<%
Recordset1.Close()
%>

tI RINGRAZIO, così non mi funziona aiutooooooooooooooo.