function validateForm() {
  var phone = document.getElementById('phone');
  var email = document.getElementById('email');
  var company = document.getElementById('company');

  phone.value = phone.value.replace(/[^0-9]/g,"");

  if (phone.value.length < 10) {
    alert ('Please enter a valid phone number.');
    phone.focus();
    return false;
  }

  if (email.value == '') {
    alert('Please enter an email address.');
    email.focus();
    return false;
  }

  if (company.value == '') {
    alert('Please enter a company name.');
    company.focus();
    return false;
  }

  // Check for valid phone number (just check for invliad characters)
  if (isNaN(phone.value)) {
    alert('Please enter a valid phone number.');
    phone.focus();
    return false;
  }

  // Check that email is valid.
  if (!isValidEmail(email.value)) {
    alert('Please enter a valid email address.');
    email.focus();
    return false;
  }


  return true;
}

//function to check valid email address
function isValidEmail(strEmail){
  validRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
  strEmail = document.forms[0].email.value;

  // search email text for regular exp matches
  if (strEmail.search(validRegExp) == -1) {
    return false;
  } 
  return true; 
}