When to Use Form Functions

Begin-form and end-form functions are called in fm_rd() and mn_rd() and are good for performing actions that should be done before or after the user has entered data into the form. Some uses of begin-form and end-form functions are listed below. This list is not exhaustive. You will find other uses as you develop your applications.

• nIf the user can invoke the same form from several points in a program, you can change the setting of the form and field options depending on where the form was called from. For instance, you could make some fields, which are irrelevant in the context that the form was called, SKIP fields.
  
  
• nThe end-form function can be used to transfer the contents of the data variables into permanent storage.
  
  
• nThe begin-form function can get a record from a database, and the end-form function can write a record to a database.

More:

What You Should Not Do in Form Functions

Writing and Installing Begin- and End-Form Functions