The 'F4' button located on the toolbar at the top of the page can be selected by using the corresponding F4 key on the keyboard or by using a mouse click.

F4 - Delete

When this button appears in the toolbar, you can select F4 to delete the current record.

Example

F4 - Zero

When this button appears in the toolbar in Enter Stock Check Figure, you can select F4 to record a 0 value