// REQUIRES JQUERY

// when the page is ready
$(function() {
    // when the submit button is clicked
    $('#submit-button').on('click', function(e) {
      // clear out all the error messages
       $('.error-field').removeClass('error-field');

       // grab the values of the text boxes
       var username = $('#username').val();
       var email = $('#email').val();
       var password = $('#password').val();

       // starts off valid
       var valid = true;

       // if username is blank, it's invalid and adds errors to the username label/field
       if(username === "" || username == null) {
           valid = false;
           $('#label-username').addClass('error-field');
           $('#username').addClass('error-field');
       }

       // if email is blank, it's invalid and adds errors to the email label/field
       if(email === "" || email == null) {
           valid = false;
           $('#label-email').addClass('error-field');
           $('#email').addClass('error-field');
       }

       // if password is blank, it's invalid and adds errors to the password label/field
       if(password === "" || password == null) {
           valid = false;
           $('#label-password').addClass('error-field');
           $('#password').addClass('error-field');
       }

       // if returns true, will actually POST to the server. if false, won't POST
       return valid;
    });
});