You can define a form with an area that is larger than the form window with the virtual form definition function, fm_vdef(). Virtual forms are useful for creating spreadsheets and other large data entry tasks.
Besides the form definition function, there are no differences in how you define and use a virtual form. Vermont Views automatically keeps the active area of the form within the form window. However, because the user cannot see the full scope of the form, virtual forms need to be carefully designed. See Chapter 14, "Virtual Data Forms," for more information.
Step 5: Define the items on the form.
After defining the form, you define each of the items that will appear on the form and where they will go. When writing forms in code, you must define the form items where the user enters data (fields, scrollable regions, pushbuttons, radio buttons, check boxes, and memo fields) in the order in which you want the user to move through them. Fields are numbered in the order in which you define them, starting with zero. In our example program, vvbasics.c, the last name field is item number zero and the phone number field is item number one. Thus, the user moves forward from the last name field to the phone number field.
