code: func (f *Form) NewField(label string, name string, value interface{}, showas string, fn FieldProcessor) (*Field, error) {
  	tmpField := Field{
  		Label:     label,
  		Name:      name,
  		ShowAs:    showas,
  		Value:     value,
  		Processor: fn,
  		Hidden:    false,
  	}
  	f.Fields = append(f.Fields, &tmpField)
  	return &tmpField, nil
  }
docs: // NewField appends a new Field to the Form.