关于查询的问题，请大虾们帮忙，小弟多谢了

Question

子页面左侧有一个搜框，因为多个页面调用，所以我给做成了一个用户控件left.ascx,left.ascx里面有一个动态的DropDownList里面选择新闻的种类，下面一个TextBox是输入关键字的。 因为search.aspx里面也包含left.ascx，而search.aspx右侧是一个GridView用来显示搜索的结果。问题是：搜索时总是提示型“DropDownList”的控件“Left1_ddl1”必须放在具有 runat=server 的窗体标记内我给left.ascx页面中加入<form ID="form2" runat="server">**</form则提示：
一页只能有一个服务器端 Form 标记。我认为left.ascx嵌套在search.aspx页面中应该是共用一个<form id="form1" runat="server">了。可为什么还提示
“DropDownList”的控件“Left1_ddl1”必须放在具有 runat=server 的窗体标记内呢？？急求多谢了

Answer 1

这是left.ascx的页面
<form ID="form2" runat="server">
                <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:SQLCONNECTIONSTRING %>"
                    SelectCommand="SELECT [kindID], [kindName], [parentID] FROM [tb_newsKind] WHERE ([parentID] = 0)">
                    <SelectParameters>
                        <asp:Parameter DefaultValue="0" Name="parentID" Type="Int32" />
                    </SelectParameters>
                </asp:SqlDataSource>
                <table width="195" border="0" align="center" cellpadding="0" cellspacing="0">
                  <tr>
                    <td width="64" height="30"><div align="center" class="c">按类别</div></td>
                    <td width="131" height="30"><div align="center">
                        <asp:DropDownList ID="ddl1" runat="server" DataSourceID="SqlDataSource1"
                            DataTextField="kindName" DataValueField="kindID">
                        </asp:DropDownList></div></td>
                  </tr>
                  <tr>
                    <td height="30"><div align="center" class="c">关键字</div></td>
                    <td height="30"><div align="center">
                        <label>
                            &nbsp;<asp:TextBox ID="Searchkey" runat="server" Width="90px"></asp:TextBox></label></div></td>
                  </tr>
                  <tr>
                    <td height="30" colspan="2"><div align="center">
                        <asp:Button ID="SButton" runat="server" Text="查询" OnClick="SButton_Click" />
                        <input type="submit" name="Submit2" value="重置" />
                    </div></td>
                  </tr>
                </table>
            </form>