It defines an action to be performed when the main object starts running and Cascade Navigation Style is selected. It is a Client Event that takes place before the Server Events (Start, Refresh and Load) and the ClientStart Event.
Since it is a Client Event, the possibilities and limitations are the same as for any other Client Event.
Event Cascade.Start
Event_code
EndEvent
Where:
Event_code
Code associated to the event.
Event Cascade.Start
//Call a welcome panel to be displayed.
SDWelcomePanel.Call()
EndEvent