<asp:LinkButton ID="LinkButton1" runat="server">Show Details</asp:LinkButton>
<ajaxToolkit:CollapsiblePanelExtender ID="cpe" runat="Server"
TargetControlID="Panel1" CollapsedSize="0"
ExpandedSize="300"
Collapsed="True"
ExpandControlID="LinkButton1"
CollapseControlID="LinkButton1"
AutoCollapse="False"
AutoExpand="False">
</ajaxToolkit:CollapsiblePanelExtender>
<asp:Panel ID="Panel1" runat="server" >
To add collapsible sections to your webpage,Ajax provides you with the CollapsiblePanel control.
</asp:Panel>

Collapsed Panel

Expanded Panel

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

<ajaxToolkit:TextBoxWatermarkExtender ID="TBWE2" runat="server"
TargetControlID="TextBox1"
WatermarkText="Type First Name Here">
</ajaxToolkit:TextBoxWatermarkExtender>

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:RequiredFieldValidator ID="RFD" runat="server"
ControlToValidate="TextBox1" ErrorMessage="Textbox should not be empty" Display="None"></asp:RequiredFieldValidator>
<ajaxToolkit:ValidatorCalloutExtender
runat="Server"
ID="ValidatorCalloutExtender 1"
TargetControlID="RFD"
Width="350px"/>

ValidatorCallout Sample

<ajaxToolkit:Accordion ID="MyAccordion" runat="server" SelectedIndex="0"
FadeTransitions="false" FramesPerSecond="40" TransitionDuration="250"
AutoSize="None" RequireOpenedPane="false" SuppressHeaderPostbacks="true">

<Panes>

<ajaxToolkit:AccordionPane ID="AccordionPane1" runat="server">

<Header><a href="">1. AccordionPane1</a></Header>

<Content>

Type your content here</Content>

</ajaxToolkit:AccordionPane>

<ajaxToolkit:AccordionPane ID="AccordionPane2" runat="server">

<Header><a href="">2. AccordionPane2</a></Header>

<Content>

content goes here

</Content>

</ajaxToolkit:AccordionPane>

</Panes>

</ajaxToolkit:Accordion>

<ajax:TabContainer Id="tabContainer" runat="server" Height="506px" Width="100%"

style="margin-right: 86px" ActiveTabIndex="0" >

<ajax:TabPanel runat="server" HeaderText="TabPanel1" ID="TabPanel1">

<HeaderTemplate>

TabPanelName//Just add a name according to your need

</HeaderTemplate>

<ContentTemplate>

Name

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

<asp:Button ID="Button1" runat="server" Text="Button" />

</ContentTemplate>

</ajax:TabPanel>

</ajax:TabContainer>

Note that the tabcontainer prefix starts with ajax( ajax:TabContainer>).
The prefix is the same as that given when the namespace was registered.

TabContainer

It provides client-side date-picking functionality with customizable date format and UI in a popup control.

<asp:TextBox ID=”TextBox1″ runat=”server”></asp:TextBox>

<ajax:CalendarExtender ID=”CalendarExtender1″ runat=”server”

TargetControlID=”TextBox1″ Format=”yyyy-MM-dd” Enabled=”True”>

</ajax:CalendarExtender>

Calender Extender