<form name="form1" method="post" action="">
<table width="83%" border="0" cellpadding="0" cellspacing="0">
<tr bgcolor="#C9E4E4">
<td width="23%" bgcolor="#C9E4E4"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Cerca
per </font></td>
<td width="77%"> <div align="left"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Operatore
<select name="operatore">
<option value=""></option>
<option>TIM</option>
<option>WIND</option>
<option>VODAFONE</option>
<option>TRE</option>
</select>


Data Scontrino : DA
<input name="data1" type="text" id="data1">
A
<input name="data2" type="text" id="data2">
</font></div></td>
</tr>
<tr>
<td><font size="2" face="Verdana, Arial, Helvetica, sans-serif">oppure</font></td>
<td><div align="right"></div></td>
</tr>
<tr bgcolor="#C9E4E4">
<td><font color="#000000" size="2" face="Verdana, Arial, Helvetica, sans-serif">Cerca
per</font></td>
<td> <div align="left"><font color="#000000"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Serial
Number
<input name="codice_alphyra" type="text" id="codice_alphyra">
</font></font></div></td>
</tr>
</table>
<input name="idpdv" type="hidden" id="idpdv" value="<%=idpdv%>">
<input name="codice_alphyra" type="hidden" id="codice_alphyra" value="<%=codice_alphyra%>">
<input type="submit" name="Submit" value="Invia">
<font size="1" face="Verdana, Arial, Helvetica, sans-serif">
</font>
</form>


e questa è la select che non mi applica la condizione (if codice_alphyra = "" then )
<%
if codice_alphyra = "" then
SQL = "SELECT * FROM scontrini WHERE idpdv= '"&idpdv&"' "
else
SQL = "SELECT * FROM scontrini WHERE idpdv= '"&idpdv&"' and codice_alphyra='"&codice_alphyra&"' "
end if
Set rec = Server.CreateObject("ADODB.Recordset")
Set rec=Conn.Execute(SQL)
%>
<% response.write codice_alphyra
%>