Menu field:MENUCALL() is provided to display the sub-menu associated with the current menu field. If you use MENUCALL() for the action function, you should specify a pointer to a menu form, either in the sub_fmp argument in the mnf_def() call or in the "Menu Field Basic Information" dialog box in the Designer.
MENUCALL() calls mn_proc() for the sub-menu associated with the current menu field. If mn_proc() fails, MENUCALL() returns FUNCERROR. Otherwise, the return is SAMELEVEL.
