Note
If you use the Visual Studio designer to edit the collection of image areas, custom attributes on the image area items will be lost (i.e. things like onmouseover or other such attributes that are not normal properties of the image area object). This appears to be a bug in the designer as the same thing happens to ListItem objects in controls such as the ListBox and DropDownList. Use code to add custom attributes to the image areas instead as show in the demo.