Figure 29.1 shows the control flow while editing a data field. Note that the processing of a field can be bypassed if the next action code is changed in the begin-field function. Keystroke processing for the field continues until an event function indicates that the current item is to be changed. If the user exited the field normally, the end-field function and validation functions are called. If either of the validation functions fail, the user is returned to the same field to correct the entry.
