function student_information() {
  $('form[name=regform]').submit(function(){
    return student_validation();
  });

  $('tr#com_city_row').hide();

  $('select#com_country').change(function(){
    if ( this.value == 'Malaysia' ) {
      $('tr#com_city_row').show();
    } else {
      $('tr#com_city_row').hide();
    }
  });
}



function mail_check(mail) {
  if (mail == undefined) //mail is empty
    return "^[-'\\w]+(?:\\.[-'\\w]+)*@[-\\w]+(?:\\.[-\\w]+)+$";
  else
    return /^[-'\w]+(?:\.[-'\w]+)*@[-\w]+(?:\.[-\w]+)+$/.test(mail); //
}


function check_form(form_element, regex_string, error_message) {
  var re = new RegExp(regex_string);
  if (!form_element.value.match(re)) {
    if (error_message != undefined) {
      alert(error_message); //if error is sent, alert. else, return value only
      form_element.focus();
    }
    return false;
  }
  return true;
}

function student_validation() {

  // Check Student ID
  if (!check_form(document.regform.stu_id, '.+', 'Student ID cannot be empty'))
    return false;

  if (!check_form(document.regform.stu_id, '^\\d{10}$', 'Student ID must be 10-digit numbers'))
    return false;

  // Check Student Name
  if (!check_form(document.regform.stu_name, '.+', 'Student name cannot be empty'))
    return false;

 // Check Email
  if (!check_form(document.regform.stu_email, mail_check(), 'This is not a valid email address'))
    return false;

 // Check Company Name
  if (!check_form(document.regform.com_name, '.+', 'Company Name cannot be empty'))
    return false;

  // Check Company Country
  if (!check_form(document.regform.com_country, '.+', 'Country cannot be empty'))
    return false;

  if (check_form(document.regform.com_country, '^Malaysia$'))
    if (!check_form(document.regform.com_city, '.+', 'City cannot be empty'))
      return false;

  return true;
}