Check Box Display Type

A check box is a control that displays a choice between states. They can be used for two mutually exclusive states such as On and Off, or Yes and No. However, it is sometimes possible that a value is allowed to be NULL, in which case the undefined state can be selected.

If there are more than two valid (i.e. non-empty) states to choose from, use option buttons, or a dropdown list box.

The On/Off state of one check box must not influence the state of another check box. If the choices between the states are mutually exclusive, use option buttons.

Guidelines for the use of check boxes are:

·	Only use check boxes when two options rule each other out.

·	Use value 1 for cleared, and 2 for checked. This will ensure that cleared is the default. Note that you can only use the undefined state for non-mandatory columns.

·	Do not use check boxes to choose between male and female, or other such pairs, for a cleared (i.e. empty) Male box only indirectly implies Female.

·	If check boxes more or less pertain to the same topic (for example if they both have to do with printing), use the Windows Designer to place them near each other on the window.