function validateEmail(address) {
  var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
  if(reg.test(address) == false)
    return false;
  return true;
}

function checkAppointmentForm() {
  if(document.getElementById('vehicle_year').value == '') {
    alert('Please enter the year of your vehicle.');
    document.getElementById('vehicle_year').select();
    return false;
  }
  if(document.getElementById('vehicle_make').value == '') {
    alert('Please enter the make of your vehicle.');
    document.getElementById('vehicle_make').select();
    return false;
  }
  if(document.getElementById('vehicle_model').value == '') {
    alert('Please enter the model of your vehicle.');
    document.getElementById('vehicle_make').select();
    return false;
  }
  if(document.getElementById('vehicle_mileage').value == '') {
    alert('Please enter the mileage on your vehicle.');
    document.getElementById('vehicle_make').select();
    return false;
  }
  if(document.getElementById('vehicle_license_plate_number').value == '') {
    alert('Please enter your vehicle\'s license plate number.');
    document.getElementById('vehicle_license_plate_number').select();
    return false;
  }
  if(document.getElementById('appointment_time').value == '') {
    alert('Please choose your desired appointment time.');
    return false;
  }
  if(document.getElementById('appointment_date').value == '') {
    alert('Please enter your desired appointment date.');
    document.getElementById('appointment_date').select();
    return false;
  }
  if(document.getElementById('first_name').value == '') {
    alert('Please enter your first name.');
    document.getElementById('first_name').select();
    return false;
  }
  if(document.getElementById('last_name').value == '') {
    alert('Please enter your last name.');
    document.getElementById('last_name').select();
    return false;
  }
  if(validateEmail(document.getElementById('email_address').value) == false) {
    alert('Please enter a valid email address.');
    document.getElementById('email_address').select();
    return false;
  }
  if(document.getElementById('address').value == '') {
    alert('Please enter your address.');
    document.getElementById('address').select();
    return false;
  }
  if(document.getElementById('city').value == '') {
    alert('Please enter your city.');
    document.getElementById('city').select();
    return false;
  }
  if(document.getElementById('state').value == '') {
    alert('Please choose your state.');
    return false;
  }
  if(document.getElementById('zip_code').value == '') {
    alert('Please enter your zip code.');
    document.getElementById('zip_code').select();
    return false;
  }
  if(document.getElementById('work_requested').value == '') {
    alert('Please describe the work requested.');
    document.getElementById('work_requested').select();
    return false;
  }
  return true;
}

function checkContactForm() {
  if(document.getElementById('first_name').value == '') {
    alert('Please enter your first name.');
    document.getElementById('first_name').select();
    return false;
  }
  if(document.getElementById('last_name').value == '') {
    alert('Please enter your last name.');
    document.getElementById('last_name').select();
    return false;
  }
  if(validateEmail(document.getElementById('email_address').value) == false) {
    alert('Please enter a valid email address.');
    document.getElementById('email_address').select();
    return false;
  }
  if(document.getElementById('phone_number').value == '') {
    alert('Please enter your phone number.');
    document.getElementById('phone_number').select();
    return false;
  }
  if(document.getElementById('appointment_time').value == '') {
    alert('Please choose your desired appointment time.');
    return false;
  }
  if(document.getElementById('appointment_date').value == '') {
    alert('Please enter your desired appointment date.');
    document.getElementById('appointment_date').select();
    return false;
  }
  if(document.getElementById('best_time_to_contact').value == '') {
    alert('Please enter the best time to contact you.');
    document.getElementById('best_time_to_contact').select();
    return false;
  }
  if(document.getElementById('work_requested').value == '') {
    alert('Please describe the work requested.');
    document.getElementById('work_requested').select();
    return false;
  }
  return true;
}

function checkMailingListForm() {
  if(document.getElementById('mailing_list_fname').value == '') {
    alert('Please enter your first name.');
    document.getElementById('mailing_list_fname').select();
    return false;
  }
  if(document.getElementById('mailing_list_lname').value == '') {
    alert('Please enter your last name.');
    document.getElementById('mailing_list_lname').select();
    return false;
  }
  if(validateEmail(document.getElementById('mailing_list_email').value) == false) {
    alert('Please enter a valid email address to join our mailing list.');
    document.getElementById('mailing_list_email').select();
    return false;
  }
  return true;
}