CHECKBOX controls are used to allow the user to select multiple options on a form.The user cicks on a CHECKBOX to select or deselect it. Clicking on a CHECKBOX toggles it. If it is currently selected, clicking on it deselects it. If it is currently deselected, clicking on it selects it. Multiple checkboxs can be selected at the same time.
CHECKBOXs must be bound to a form via a CHECK_FRAME. All CHECKBOXs to be used as one group are bound by a single CHECK_FRAME. Multiple groups of CHECKBOXs are allowed via seperate CHECK_FRAMES. CHECKBOXs and RADIO_BUTTONs can be mixed in the same CHECK_FRAME.
When RADIO_BUTTONs and CHECKBOXs are mixed in the same CHECK_FRAME, the behaviour tends to be (can be overriden by the programmer, but by default is):
- clicking on a CHECKBOX does NOT affect other CHECKBOXs
- clicking on a CHECKBOX DOES affect other RADIO_BUTTONs (they are normally turned off)
It is possible to explicitly set the truth value of a CHECKBOX or RADIO_BUTTON control. This truth value is used by the CHECK_FRAME control to determin the value used when invoking the CHECK_FRAME log function. It is possible to overlap truth values from multiple CHECKBOX and RADIO_BUTTON controls. Using carfully selected values (sets of bits) it is possible to use one RADIO_BUTTON or CHECKBOX control to activate several other RADIO_BUTTON or CHECKBOX controls simultaniously.