Every time button cause full post back, even it is in update panel

Question

In my code every DropDownList is inside an Update Panel and they're not postbacking. For each button click full postback occurs, but my buttons are in Update Panel. I tried using the asynpostback trigger, in that case server side message is not displayed. I want that message also.

My code is:

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true">
    </asp:ScriptManager>
    <table align="center" style="border: thin solid #FF0000" width="80%">
        <tr>
            <th colspan="2" align="center" bgcolor="Black" style="color: #FFFFFF">
                Schedule New Batch
            </th>
        </tr>
        <tr>
            <td colspan="2" align="center">
                <div>
                    <asp:Label ID="lblError" runat="server" Style="font-weight: 700; color: #FF0000;"
                        Text="Label" Visible="False"></asp:Label>
                    <asp:Label ID="lblSucess" runat="server" Style="font-weight: 700; color: #006600;
                        background-color: #FFFFFF;" Text="Label" Visible="False"></asp:Label>
                </div>
            </td>
        </tr>
        <tr>
            <td colspan="2">
                &nbsp;
            </td>
        </tr>
        <tr>
            <td class="style44" align="right">
                Technology<span class="style23">*</span> :
            </td>
            <td class="style45">
                <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                    <ContentTemplate>
                        <asp:DropDownList ID="ddlTechnology" runat="server" Width="155px" Class="valid" OnSelectedIndexChanged="ddlTechnology_SelectedIndexChanged"
                            AutoPostBack="True" Height="23px">
                        </asp:DropDownList>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </td>
        </tr>
        <tr>
            <td class="style49" align="right">
                Courses<span class="style23">*</span> :
            </td>
            <td class="style50">
                <asp:UpdatePanel ID="UpdatePanel2" runat="server">
                    <ContentTemplate>
                        <asp:DropDownList ID="ddlCourse" runat="server" Width="155px" Class="valid" OnSelectedIndexChanged="ddlCourse_SelectedIndexChanged"
                            AutoPostBack="True" Height="23px">
                        </asp:DropDownList>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </td>
        </tr>
        <tr>
            <td class="style9" align="right">
                Faculty<span class="style23">*</span> :
            </td>
            <td class="style47">
                <asp:UpdatePanel ID="UpdatePanel3" runat="server">
                    <ContentTemplate>
                        <asp:DropDownList ID="ddlFaculty" runat="server" Width="155px" Class="valid" OnSelectedIndexChanged="ddlFaculty_SelectedIndexChanged"
                            AutoPostBack="True" Height="23px">
                        </asp:DropDownList>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </td>
        </tr>
        <tr>
            <td class="style44" align="right">
                Timing<span class="style24">*</span> :
            </td>
            <td class="style45">
                <asp:UpdatePanel ID="UpdatePanel4" runat="server">
                    <ContentTemplate>
                        <asp:DropDownList ID="ddlTiming" runat="server" Width="155px" Height="23px" AutoPostBack="True"
                            Class="valid" OnSelectedIndexChanged="ddlTiming_SelectedIndexChanged">
                        </asp:DropDownList>
                        <asp:Button ID="btnAdd" runat="server" Text="Add" />
                        <cc1:modalpopupextender id="btnAdd_ModalPopupExtender" runat="server" cancelcontrolid="btnCancleInsertTime"
                            dynamicservicepath="" enabled="True" popupcontrolid="Panel1" targetcontrolid="btnAdd">
                </cc1:modalpopupextender>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </td>
        </tr>
        <tr>
            <td class="style44" align="right">
                Start Date<span class="style23">*</span> :
            </td>
            <td class="style45">
                <asp:UpdatePanel ID="UpdatePanel6" runat="server">
                    <ContentTemplate>
                        <asp:TextBox ID="txtInsertdate" runat="server" Width="150px" Height="16px" Class="valid"></asp:TextBox>
                        <cc1:calendarextender id="CalendarExtender1" runat="server" targetcontrolid="txtInsertdate"
                            format="yyyy-MM-dd">
                </cc1:calendarextender>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </td>
        </tr>
        <tr>
            <td class="style51">
                &nbsp;
            </td>
            <td class="style45">
                &nbsp;
            </td>
        </tr>
        <tr>
            <td>
                <div style="text-align: right">
                    <asp:Button ID="btnSchedule" runat="server" Text="Schedule" Style="font-weight: 700;
                        margin-left: 0px;" Width="81px" Height="24px" OnClick="btnSchedule_Click" />
                </div>
            </td>
            <td>
                <asp:UpdatePanel ID="UpdatePanel5" runat="server">
                    <ContentTemplate>
                        <asp:Button ID="btnreset" runat="server" OnClick="btnreset_Click" Style="font-weight: 700"
                            Text="Reset" Width="67px" CausesValidation="False" UseSubmitBehavior="false" />
                    </ContentTemplate>
                    <Triggers>
                        <asp:PostBackTrigger ControlID="btnreset" />
                    </Triggers>
                </asp:UpdatePanel>
            </td>
        </tr>
        <tr>
            <td colspan="3">
                <asp:Panel ID="Panel1" runat="server" aline="center">
                    <table style="border: thin solid #FF0000; background: #7F8778">
                        <tr>
                            <th class="style53">
                                Please Add a Time
                            </th>
                        </tr>
                        <tr>
                            <td align="center" style="color: #FF0000" class="style53">
                                <asp:TextBox ID="txtInsertTime" runat="server" Width="124px"></asp:TextBox>
                                &nbsp; EX: 09:15AM
                            </td>
                        </tr>
                        <tr>
                            <asp:UpdatePanel ID="UpdatePanel7" runat="server">
                                <ContentTemplate>
                                    <td align="center" class="style53">
                                        <asp:Button ID="btnInsertTime" runat="server" Text="Add Time" Width="73px" OnClientClick="return InsertTime()"
                                            OnClick="btnInsertTime_Click" class="cancel" />
                                        &nbsp; &nbsp;
                                        <asp:Button ID="btnCancleInsertTime" Text="Cancel" Width="55px" runat="server" class="cancel" />
                                    </td>
                                </ContentTemplate>
                            </asp:UpdatePanel>
                        </tr>
                    </table>
                </asp:Panel>
            </td>
        </tr>
    </table>
    <br />
    </form>
</asp:Content>

Solution

I've tried your code in a blank Solution, using Visual Studio 2010, .NET Framework 4.0. Changing the following, I manage to avoid the full postback from the buttons:

I've added the AsyncPostBackTriger property for the Click event for each button and SelectedIndexChanged for the DropDownLists. Also I've configured the UpdatePanel properties ChildrenAsTriggers="false" and UpdateMode="Conditional". Following the same approach for every UpdatePanel will do the trick.

<asp:UpdatePanel ID="UpdatePanel4" runat="server" ChildrenAsTriggers="false" UpdateMode="Conditional">
    <Triggers>
        <asp:AsyncPostBackTrigger ControlID="ddlTiming" EventName="SelectedIndexChanged" />
        <asp:AsyncPostBackTrigger ControlID="btnAdd" EventName="Click" />
    </Triggers>
    <ContentTemplate>

        <asp:DropDownList ID="ddlTiming" runat="server" Width="155px" Height="23px" AutoPostBack="True"
            Class="valid" OnSelectedIndexChanged="ddlTiming_SelectedIndexChanged">
        </asp:DropDownList>
        <asp:Button ID="btnAdd" runat="server" Text="Add" />
        <cc1:modalpopupextender id="btnAdd_ModalPopupExtender" runat="server" cancelcontrolid="btnCancleInsertTime"
            dynamicservicepath="" enabled="True" popupcontrolid="Panel1" targetcontrolid="btnAdd">
        </cc1:modalpopupextender>
    </ContentTemplate>
</asp:UpdatePanel>

I've noticed that the button Schedule was not inside an Update Panel, so obviously it was causing full page postback.