更新面板不工作在asp.net code

这是我的C＃$ C $后面

This is my c# code behind

protected void callDispositionChanged(object sender, EventArgs e)
{
    var dropDown = (DropDownList)ListView1.FindControl("callDispositionSelector");
    var visitID = (TextBox)ListView1.FindControl("visitID");
    if (dropDown != null)
    {
        Response.Write(dropDown.SelectedValue + "ssssssssss");
        visitID.Text = dropDown.SelectedValue;
    }
    else
    {
        visitID.Text = "ffffff";
        Response.Write("FFFFFFFFFFFFFFFF");
    }               
}

这是我的ASP code

this is my asp code

<asp:UpdatePanel ID="UpdatePanel3" UpdateMode="Conditional" runat="server">
                        <ContentTemplate>
                        <tr class="footer" runat="server">
                            <td colspan="4" runat="server">* By VoiceMpower
                               <asp:DropDownList AutoPostBack="true" runat="server"  ID="callDispositionSelector" OnSelectedIndexChanged="callDispositionChanged" clientidmode="Static">
                                   <asp:ListItem Value="-1">Select Disposition Reason</asp:ListItem>
                                   <asp:ListItem Value="1">Reservation</asp:ListItem>
                                   <asp:ListItem Value="2">Change of Reservation</asp:ListItem>
                                   <asp:ListItem Value="3">Cancellation</asp:ListItem>
                                   <asp:ListItem Value="4">Wait List</asp:ListItem>
                                   <asp:ListItem Value="5">Other</asp:ListItem>
                               </asp:DropDownList>
                                <asp:TextBox runat="server" ID="visitID" clientidmode="Static"></asp:TextBox>
                            </td>
                        </tr>
                         </ContentTemplate>
                    </asp:UpdatePanel>

当我改变选择的值，函数被执行，但结果（后背页）已经在devaul vaule选择。

when I change the value of the select, the function is executed, but the results (the post back page) has the select in the devaul vaule.

我已经有

<asp:ScriptManager ID="ScriptManager2" runat="server" />

注释3

这是ASP code在 asp.listview

我无法调试该项目，因为在服务器和数据库，我不能做一个链接。所以，我每开发一个functoin的时候，我去部署在服务器上的网站并进行测试。所以，请让你的答案未做破发点和类似的东西。在此先感谢

I can't debug the project because the database on the server and I am not allowed to make a link to it. So each time i develop a functoin, I go and deploy the website on the server and test it. So please let your answers without making break points and something like that. thanks in advance