Menu field:CHECKMARK() toggles the display of the checkmark character for the current menu field. If you use CHECKMARK() as the action function, specify NULLP as the pointer to the sub-form, either as the sub_fmp argument in the mnf_def() call, or by leaving the field blank in the Designer "Menu Form Basic Information" dialog box. If you do specify a sub-form pointer, it will be ignored. You must also set the checkmark character to use for the menu form, either in the Designer or by calling smn_checkmark(). See Chapter 21, "Changing the Appearance of Menus," for more information about using checkmarks on menu forms.
If you enable checkmarks for a menu by calling smn_checkmark(), Vermont Views requires a space in front of every field for a checkmark character, even if that particular field does not use a checkmark. If you do not leave a space in front of the field, Vermont Views will overwrite the first character of the menu field text.
CHECKMARK() checks the checkmark status of the current menu field. If the checkmark status is ON, it is changed to OFF. If the status is OFF, it is changed to ON. Vermont Views redisplays the menu with the new checkmark status. If you have not set the checkmark character to use for the menu, the function beeps and returns.
CHECKMARK() returns SAMELEVEL.
