Toggle Button Control [Access 2003 VBA Language Reference]
A toggle button on a form is a stand-alone control used to display a Yes/No value from an underlying record source.
When you click a toggle button that's bound to a Yes/No field, Microsoft Access displays the value in the underlying table according to the field's Format property (Yes/No, True/False, or On/Off).
Toggle buttons are most useful when used in an option group with other buttons.
You can also use a toggle button in a custom dialog box to accept user input.