Then, assign the Target Content - which is the HTML element or elements that you wish to assign your Tool-Tip to. There are two possible ways to do this.
A. The ControlToToolTip Property
If your Target Content is a single ASP.NET control, such as a Panel or a ImageButton, set the ControlToToolTip property to point to this ASP.NET control.
B. The TargetContentTemplate
The other option is to use the TargetContentTemplate. If you choose to use the Template, leave ControlToToolTip blank.