列表值不稳定

<%
 strhui="select * from huiyuan"
 set rs_huiyuan=conn.execute(strhui)
 %>
  客户:
    <select name="huiyuan" id="huiyuan" onChange="form2.submit()">
   
        <option value="所有客户">所有客户</option>
            
      <%
    do while rs_huiyuan.eof=false
    %>
    <option value="<%=rs_huiyuan("username")%>"><%=rs_huiyuan("username")%></option>
        <%
      rs_huiyuan.movenext
    loop
    %>
    </select>
选择值后一闪,又回到"所有客户"了.不知什么原因.调了一天,还是没找到问题.请高手帮看看.