title: Validate button must be clicked before closing workbook
body: <p>If user changes/writes into excel sheet then he must click the validate button.If he changes data and tries to save/close excel,pop up must be show to the user. Simply I want to check whether used clicks validate button before closing the workbook. If a single letter is changed by user, user needs to click on validate button. After clicking on validate button ,if user again changes any data ,then too user must get warning that validate before saving/closing.</p>