TextBoxWatermark is an ASP.NET AJAX extender that can be attached to an ASP.NET TextBox
control to get "watermark" behavior. When a watermarked TextBox is empty, it displays a
message to the user with a custom CSS style. Once the user has typed some text into the
TextBox, the watermarked appearance goes away. The typical purpose of a watermark is to
provide more information to the user about the TextBox itself without cluttering up the
rest of the page.
The control above is initialized with this code. The italic properties
<ajaxToolkit:TextBoxWatermarkExtender ID="TBWE2" runat="server"
WatermarkText="Type First Name Here"