AJAX Toolkit Watermark extender example

AJAX  Toolkit provides a variety of controls and extenders.
In this blog  I would discuss use of Watermarkextender to

1. <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default"%>
2. 
   
3. <%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="cc1" %>
4. <cc1:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"> </cc1:ToolkitScriptManager>
5. 
   
6. <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox><br />
7. 
   
8. <cc1:TextBoxWatermarkExtender ID="TextBoxWatermarkExtender1"  TargetControlID="TextBox2" WatermarkText="Enter username here" runat="server">
9. </cc1:TextBoxWatermarkExtender>

Above code is example of  TextBoxWatermarkExtender .

It has two important properties "TargetControlID" and "WatermarkText"

TargetControlID: tells to which control this extender is attached.
WatermarkText: tells the text which would be displayed in target control attached with TextBoxWatermarkExtender.
Note1: When you are using  ajax toolkit controls always use ToolkitScriptManager instead of ScriptManager.

Note2:If you got the error(Could not load type 'System.Web.UI.ScriptReferenceBase' from assembly 'System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35').
Use the ScriptManager instead of  ToolkitScriptManager .