In our previous column we introduced Behaviors, the most significant new JavaScript feature of Internet Explorer 5.0. We have shown how to write a behavior scriptlet and how to communicate between the scriptlet and the containing page. This interface handling is accomplished by the Behavior Handler. The Behavior Handler:

• Notifies the behavior scriptlet of certain occurrences, such as when the calling document is loaded.
• Exposes custom events to the calling page.
• Exposes the element that the behavior is associated with to the scriptlet.

We explain the Behavior Handler via a new example, the popular Connect Three game. It is played by two opponents on a 3x3 board. Each opponent, in his or her turn, places a game piece in one of the unoccupied board locations. In our example, one opponent is using "X"s and the other one is using "O"s. The first to accomplish a row, a column, or a diagonal of identical pieces is the winner.

• How to use the Behavior Handler's event element.
• How to use the Behavior Handler's element property.
• How to use the Behavior Handler's attachNotification() method.
• How to use the Behavior Handler's createEventObject() method.
• How to use the Behavior Handler's fireEvent() method.
• How to use the Behavior Handler's attachEvent() and detachEvent() methods.
• How to specify the Behavior Handler's location.
• How to use the Behavior Handler's uniqueID property.

At this point you may also view the entire file for the hosting page and the behavior scriptlet.