Fires after the operator presses down the mouse button if one of the following events occurs:
Definition Level form, block, or item
SELECT statements, restricted Built-ins, unrestricted Built-ins
Enter Query Mode yes
Use a When-Mouse-Down trigger to perform an action every time the operator presses down the mouse button within an item and/or canvas.
Note: The mouse down event is always followed by a mouse up event.
no effect
Depending on the window manager, navigational code within a When-Mouse-Down trigger may fail. For example on Microsoft Windows, if the operator clicks the mouse button within a field (Item_One), a When-Mouse-Down trigger that calls GO_ITEM ('item_two') will fail because Windows will return focus to Item_One, not Item_Two since the When-Mouse-Up event occurred within Item_Two.