function checkCheckBox(f) {
  if (f.agree.checked == false) {
    alert('Please confirm that you have read VIN Terms and Conditions');
    return false;
  } 

  else if (f.Name.value == "") {
    alert('Please enter fullname');
    return false;
  } 

  if ((f.email.value == "") || 
(f.email.value.indexOf('@') == -1) || 
(f.email.value.indexOf('.') == -1)) {
alert("Please enter email");
return false;
}

  else if (f.security_code.value == "") {
    alert('Please enter security code');
    return false;
  } 
  
  else
    return true;
}