[PHP] Email validation considering PHP version
function isValidEmail($email)
{
if(version_compare(PHP_VERSION, '5.2.0', '>=')
return filter_var($email, FILTER_VALIDATE_EMAIL);
else
return eregi('^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$', $email);
}