Check Boxes
Click the box beside or after an option to select or clear the check box. When you click an empty box, a check mark or an X appears in the box. If you click a box that is selected, then the check mark or X disappears.
In query mode, check boxes have a third possible state. For more information about using check boxes in query mode, see Tips for Queries.
You can press the space bar to select and deselect check boxes.