Add UserControl Dynamically in Panel Control asp.net page - asp.net

Question

I am creating a website where user gives some value in textbox and clicks a button.
On the button click the UserControl should be added for number of time the user has given input.
What I did is,
protected void btnSearchTaxi_Click(object sender, EventArgs e)
{
for (int i = 0; i < 4; i++)
{
CustomDisplayList cus = new CustomDisplayList();
cus.ID = "cus" + i;
cus.Visible = true;
pnlSearchResult.Controls.Add(cus);
}
}
CustomDisplayList is my user control which is complex control [mixture of labels, textbox, button].
<td style="width:20%; font-family: Century Gothic; font-size:12px; color:White; text-
align:center;">Click to find<br/>
<asp:Button ID="btnSearchTaxi" runat="server" Text="Search Taxi" CssClass="googleButton"
Width="200px" onclick="btnSearchTaxi_Click" />
</td>
<td style="height:150px; width:100%; background-color: #FF6600">
<table style="height:100%; width:100%">
<tr><td style="color:White; font-size:30px; ">Search Result :</td></tr>
<tr><td><asp:Panel ID="pnlSearchResult" runat="server"></asp:Panel>
</td></tr>
</table>
</td>
The code was executed without any error, but the Control was not generated inside the panel.
Now I have changed the CODE to something like
<asp:UpdatePanel ID="UpdatePanel3" runat="server" UpdateMode = "Conditional" >
<ContentTemplate>
<asp:Button ID="btnSearchTaxi" runat="server" Text="Search Taxi" CssClass="googleButton" Width="200px" onclick="btnSearchTaxi_Click" />
</ContentTemplate>
</asp:UpdatePanel>
<asp:UpdatePanel ID="UpdatePanel4" runat="server" UpdateMode = "Conditional">
<ContentTemplate>
<asp:Panel ID="pnlSearchResult" runat="server" Width="100%" Height="200px" BackColor="Aquamarine"></asp:Panel>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID = "btnSearchTaxi" EventName="Click"/>
</Triggers>
</asp:UpdatePanel>
But the still the Dynamic usercontrol are not getting created.