There are two ways to process a form in Vermont Views. The simplest method is to call the highest-level form processing function, fm_proc() or mn_proc(). These high-level functions, in turn, call lower-level functions: fm_up() or mn_up(), to initialize the form and put it on the screen, and fm_rd() or mn_rd(), to allow the user to type information into the form or make menu selections. If you use fm_proc() or mn_proc(), the form is taken off the screen automatically when the user exits or aborts the form. An alternate method of processing a form, which is discussed further in Chapter 35, "Controlling Form Processing at Lower Levels," is to call fm_up(), fm_rd() and fm_dn() (or mn_up(), mn_rd() and mn_dn() for menus) directly in your code. This method allows you to have more control over when the form is put on the screen and when it is taken down.
Internally, these two methods are almost equivalent. This chapter will discuss fm_proc() and mn_proc(), and the processing that takes place during those functions. You will find references to fm_up() and fm_rd() as well.
