How to maintain hash tab change on post back using Asp.net?

How to maintain hash tab change on post back using Asp.net?

When I click on the button inside the tab, it's loading the page and it
returns to the first Tab.. Here is my code:
<div id="myTabContent" class="tab-content">
<ul class="nav nav-tabs">
<li class="active"><a href="#AFRICA" data-toggle="tab">AFRICA</a></li>
<li><a href="#EUROPE" data-toggle="tab">EUROPE</a></li>
<li><a href="#AMERICA" data-toggle="tab">AMERICA</a></li>
</ul>
<div class="tab-pane active in" id="AFRICA">
<asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1">
<ItemTemplate>
<asp:Button id="tr" OnClick="trd_clk1" runat="server" text='<%#
Bind("trade") %>' UseSubmitBehavior="False" CommandName="tr"
CommandArgument='<%# Bind("trade") %>' CssClass="btn btn-primary"
CausesValidation="False"/>&nbsp;&nbsp;&nbsp;
</ItemTemplate>
</asp:Repeater>
</div></div>
I did the same thing for the other tabs..
Thank you!