Event Variables are created when an event starts. To use them, they must be linked to parameters in the event's script call. The following example is a procedure call linked to the KeyDown event of AnObject.

Sub AnObject_KeyDown(KeyCode, Shift)

Notice that this call contains variables KeyCode and Shift. E3 automatically assigns values to these variables when this event occurs. In this case, KeyCode receives the code of the pressed key and Shift is True or False, whether the SHIFT key is pressed or not.