To define event handler for a component, switch to design mode, click on component design button and in Events menu select event.
Event designer contains two scripts - Client Script and Server script
Client script is written in javascript and executes in browser, server script is written in pascal and executes on server. Client script can call server script functions using methods of Server or AsyncServer object.
For more details please refer to Actions Server Script and Actions Client Script topics.
Client script can use following variables:
•frame - current frame element
•component = sender - current component
•event - event name
•item - component item. For example on sitebar.change event it will contain selected sidebar element.