func EnterNewContact(UI ui.UserInterface) ([]string, error) { var fields = []string{ "email address", "phone number", } var uris = []string{ "mailto:", "tel:", } var contacts []string values, err := UI.FormInput("Enter contact data, leave fields empty to omit them", fields) if err != nil { return nil, err } for ndx, value := range values { if 0 != len(value) { contacts = append(contacts, uris[ndx]+value) } } return contacts, nil }