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 validatePhone(phone)
{
  var reg = /^[2-9]\d{2}-\d{3}-\d{4}$/;
  if(reg.test(phone) == false)
    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(document.getElementById('organization').value == '')
  {
    alert('Please enter your organization.');
    document.getElementById('organization').select();
    return false;
  }
  if(document.getElementById('comments').value == '')
  {
    alert('Please enter some comments/questions.');
    document.getElementById('comments').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(validatePhone(document.getElementById('phone_number').value) == false)
  {
    alert('Please enter a valid Phone Number');
    document.getElementById('phone_number').select();
    return false;
  }
}