You can initiate an action based on which button the operator presses, whether the button pressed is button 1, 2 or 3.
You can also initiate an action based on a single click, a double-click, a single click combined with a shift modifier, and other combinations.
The following example demonstrates how to determine which mouse button is pressed when the operator clicks the mouse.
/* ** Trigger: When-Mouse-Click */
DECLARE
the_button_pressed VARCHAR(1);
BEGIN
the_button_pressed := :System.Mouse_Button_Pressed;
IF the_button_pressed = '1' THEN
Show_Window('options_window');
END IF;
END;
About mouse events, triggers, and system variables
SYSTEM.MOUSE_BUTTON_PRESSED examples