Button is not working inside update panel

Question

<asp:UpdatePanel ID="updatePanel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true">

<ContentTemplate>

<div id="fundPerformanceChart" runat="server" class="fundPerformanceChart">

<div id="chartFilter" runat="server" class="chartFilter">

<asp:Label ID="lblFundCompany" runat="server"></asp:Label>

<asp:DropDownList ID="cblFundsList" runat="server" AppendDataBoundItems="true" ClientIDMode="Static"

CssClass="cblFundsList">

</asp:DropDownList>

<br />

</div>

<div class="datePicker">

<asp:Label ID="lblfrom" runat="server"></asp:Label>

<cms:DateTimePicker ID="clndrDateFrom" runat="server" EditTime="false" DisplayNow="false"

CultureCode="en-GB" CssClass="fromDate" Visible="false" />

<input type="text" runat="server" id="clndrFrom" clientidmode="Static" />

<asp:Label ID="lblto" runat="server"></asp:Label>

<cms:DateTimePicker ID="clndrDateTo" runat="server" EditTime="false" DisplayNow="false"

CultureCode="en-GB" CssClass="toDate" Visible="false" />

<input type="text" runat="server" id="clndrTo" clientidmode="Static" />

<asp:Button ID="btnAdd" runat="server" OnClick="btnAdd_Click" Enabled="True" />

</div>

<br />

<div id='chart_div' class='chart' style='width: 630px; height: 200px !important; padding-top: 15px;'>

</div>

<div class="loading" align="center">

Loading. Please wait.<br />

<br />

<img src="../../MARKAZ/media/Markaz/Global/loader.gif" alt="Please wait" />

</div>

<asp:HiddenField ID="HiddenCompanyID" runat="server" ClientIDMode="Static" />

</div>

</ContentTemplate>

<Triggers>

<asp:AsyncPostBackTrigger ControlID="btnAdd" EventName="Click"/>

</Triggers>

</asp:UpdatePanel>