Suppose you have a required email field in your web form, bu…
Suppose you have a required email field in your web form, but do not want the user’s browser to display its built-in warning messages if the user attempts to submit the form without completing this field. You prefer to write your own JavaScript code to validate this field and take action when it is invalid. What can you place in the blank in the following command block in order to achieve this, assuming you’ve already assigned the variable email to a reference to this field?_____ { evt.preventDeFault(); commands; // Error handling code});