Show calender click on textbox.

Question

I want to show calender when click on text box in below code.

 

<tr>

<td>

<asp:Label ID="lblDob" runat="server" Text="Enter DOB" Font-Bold="True" ForeColor="#416271"></asp:Label>

<asp:Label ID="Label11" runat="server" Text="*" ForeColor="Red" Font-Size="Smaller"></asp:Label>

<asp:RequiredFieldValidator ID="reqDob" runat="server" ControlToValidate="txtDob"

ValidationGroup="submit" ForeColor="Red" ErrorMessage="*"></asp:RequiredFieldValidator>

</td>

<td style="width: 17%; height: 55px">

<asp:TextBox ID="txtDob" runat="server" CausesValidation="True" MaxLength="30" for="CalendarExtender3" />

<asp:Image ID="Image3" runat="server" ImageUrl="~/Admin/Images/edit.gif" />

<cc1:CalendarExtender ID="CalendarExtender3" runat="server" TargetControlID="txtDob"

PopupButtonID="Image3">

</cc1:CalendarExtender>

</td>

<td style="padding: 5px 5px 5px 5px; font-weight: bold; color: #416271;">

<asp:Label ID="Label1" runat="server" Text="Enter Your DOB." Font-Bold="True" ForeColor="#416271"></asp:Label>

</td>

</tr>