Can't set value to some of the controls inside tabpanel of tabcontainer

Hi guys,

I have a tabpanel inside a tabcontainer, within the tabpanel I have a few controls including textbox (single line and multi-line), checkbox.

I am able to load data into some of the controls but there are two textbox (one single line and one multi-line) failed to load data.

My original code is quite simple:

Me.txtLARReason.Text = dt.Rows(0)("ReviewDetail")

There is no error for it but txtLARReason shows blank.

I am thinking maybe inside a tabcontainer is causing the problem (although other textboxes have no issue), I tried the following:

Dim txtLARReason1 As TextBox
            txtLARReason1 = CType(TabContainer1.FindControl("tpLAR").FindControl("txtLARReason"), TextBox)
            txtLARReason1.Text = dt.Rows(0)("ReviewDetail")

And nothing changes.

The working control is:

Me.txtLARReviewer.Text = dt.Rows(0)("Reviewer")

txtLARReviewer and txtLARReason are within the same tabpanel

The frontend code is:

<cc1:TabContainer runat="server"  AutoPostBack="true" OnClientActiveTabChanged="clientActiveTabChanged"
    id="TabContainer1"
.....<cc1:TabPanel ID="tpServer" runat="server">
....<cc1:TabPanel ID="tpLAR" runat="server"><HeaderTemplate>Logical Access Review</HeaderTemplate><ContentTemplate><table class="LARReviewTable"><tr><td width="25%">
                                1.<asp:CheckBox ID="chkSOSCompleted" runat="server" 
                                    Text="SOS Activities Completed" TextAlign="Left"></asp:CheckBox><td width="25%">
                                    2. Reason(Optional):<asp:TextBox ID="txtLARReason" runat="server" 
                                        TextMode="MultiLine" Width="90%"></asp:TextBox></td><td>
                                    3. By Whom:<asp:TextBox ID="txtLARReviewer" runat="server"></asp:TextBox></td><td>
                                    4. SOS Date Completed<asp:Label ID="lblLARDate1" runat="server"></asp:Label><asp:TextBox ID="txtLARCompleteDate" runat="server" Width="120px"></asp:TextBox><img id="IMG1" alt="Date First Issued" class="NextCalendar_button" 
                                        src="../Images/calendar.png">&#160;<cc1:CalendarExtender ID="CalendarExtender1" 
                                        runat="server" Enabled="True" Format="dd/MM/yyyy" PopupButtonID="IMG1" 
                                        TargetControlID="txtLARCompleteDate"></cc1:CalendarExtender></img></td></td></tr><tr><td>
                                5. SignOff Manager:<asp:TextBox ID="txtLARManager" runat="server"></asp:TextBox></td>                            <td>
                                6. SOS Signoff Date<asp:Label ID="lblLARDate2" runat="server"></asp:Label><asp:TextBox ID="txtLARSignOffDate"  runat="server" Width="120px" ></asp:TextBox><IMG class="NextCalendar_button" id="IMG2"
												alt="Date First Issued" src="../Images/calendar.png"><cc1:CalendarExtender ID="CalendarExtender2" runat="server" Format="dd/MM/yyyy"
                                    PopupButtonID="IMG2" TargetControlID="txtLARSignOffDate" Enabled="True"></cc1:CalendarExtender></td><td>
                                Current LAR Status:</td><td>&nbsp;<asp:Label ID="lblLARStatus" runat="server"></asp:Label></td></tr></table>