Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
The HTMLFrameSetElement interface provides special properties (beyond those of the regular HTMLElement interface they also inherit) for manipulating <frameset> elements.
The following WindowonXYZ event handler properties are also available as aliases targeting the window object. However, it is advised to listen to them on the window object directly rather than on HTMLFrameSetElement.
Note: Using addEventListener() on HTMLFrameSetElement will not work for the onXYZ event handlers listed below. Listen to the events on the window object instead.