The simplest way to process a form is to call fm_proc(); the simplest way to process a menu is to call mn_proc(). Both these high-level functions put the form or menu on the screen, allow the user to enter data or make menu selections, and then remove the form or menu when the user is finished.
For some applications, you need more control over when these events happen. You may want to display the form or menu at the beginning of the application, and allow the user to enter information later. You may want to get the data the user has entered, clear the form, and allow him to enter a second set of data. In these cases, and in many others, you want more control over form processing than fm_proc() and mn_proc() allow.
fm_proc() and mn_proc() are high-level functions that call separate form functions to display a form on the screen, read the user input, convert the entered data in a data form, and remove the form from the screen. These lower-level functions are also available for your use to gain greater control over when these actions take place.
is a comprehensive function that performs in a single call the actions performed separately by fm_up(), which initializes and displays the form, fm_rd(), which reads the user input, and fm_dn(), which removes the form from the screen. Some of these functions call still lower-level functions. calls a similar group of functions to process a menu: mn_up(), mn_rd() and mn_dn().
