Add a handler to be notified when the event occurs.
"webRequestEvent_var" is a variable referencing a WebRequestEvent object. |
"webRequestEvent_var" is a variable referencing a WebRequestEvent object. |
| Type | Description |
| boolean | Returns true if the addition of the handler was successful. |
| Name | Type | Description |
| handler | WebRequestEventHandler | The handler object to be called when this event is fired. |