在asp中用sum() 加where 条件怎么样都显示空值

<script type="text/javascript">
     
                            function t24(o)
                              {
                                var s0=document.getElementById("select1<%=a%>").value
                                                              
                                 <%
                                 Set rs9=server.CreateObject("adodb.recordset")
                                 sql9="select   sum(sl) AS tal from jxc where pp='"&s0&"'"
                                                                    
                                  rs9.open sql9,conn,1,3
                                 %>
                           
                                     alert(s0)        -----这里可以正常的显示出s0的内容
                                     alert(<%=rs9(0)%>)    ----这里一直显示为空值。
                                      如果单独把 where pp='小米'   alert(<%=rs9(0)%>)又能正常显示出值
                 请各位大师指点一下了