TabContainer Advice

I am using an TabContainer inside an update panel, I have 6-7 tabs, each one contains customer data that can be edited in a ModalPopup

I just have a question if i am doing this right.

Should I have the whole TabContainer inside One Update Panel?

Should I instead have an UpdatePanel inside each Tab?

The issue I am having is validation inside a modalpopup, validation works fine, but modalpopup hides even if validation is wrong, and i want it to stay open if a required field is not entered. i am wondering if my setup has it not working correctly.

So each tab has modalpopup for content in that tab.

Just some advice on better practical programming

<ajx:TabPanel runat="server" ID="TabPanelContract" HeaderText="CONTRACT &#xf0d7;"><ContentTemplate><div class="tab-body-container"><div class="data-filter-by"><span class="title bold">Service Contract</span><asp:Label ID="Label5" runat="server" Text=": All" /><asp:LinkButton ID="LinkButton9" runat="server" PostBackUrl="~/Admin/Customers/account-create.aspx" Text="&#xf055;" CssClass="fa-2x" /><asp:LinkButton runat="server" ID="LinkButton10" Text="&#xf021;" CssClass="fa-2x" /></div><div class="data-group"><span>Lock Box Code:</span><asp:Label ID="Label11" runat="server" CssClass="label" Text="No Data" /><asp:LinkButton ID="LinkButton23" runat="server" CausesValidation="False" CssClass="fa-lg" Text="&#xf044;" /><ajx:ModalPopupExtender ID="ModalPopupExtender1" runat="server" TargetControlID="BtnEditLockBoxCode" OkControlID="BtnUpdateLockBoxCode" CancelControlID="BtnCancelUpdateLockBoxCode" PopupControlID="PnlEditLockBoxCode" ValidateRequestMode="Enabled" /><asp:Panel ID="Panel1" runat="server" CssClass="ui-form popup"><h1>Update Lock Box Code</h1><div class="form-group"><span>Enter New Lock Box Code</span><asp:TextBox ID="TextBox4" runat="server" ValidationGroup="VgLockBoxCode" /><asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="UiLockBoxCode" ValidationGroup="VgLockBoxCode" /></div><div class="button-group"><asp:Button ID="Button1" runat="server" Text="&#xf0c7; Save" ValidationGroup="VgLockBoxCode" CausesValidation="true" /><asp:Button ID="Button2" runat="server" Text="&#xf00d; Cancel" /></div></asp:Panel></div></div></ContentTemplate></ajx:TabPanel>

The reason I ask is I saw a post that if you don't want an modalpopup to close, you put an update panel in it