function isValidEmail (email, strict)
{
 if ( !strict ) email = email.replace(/^\s+|\s+$/g, '');
 return (/^([a-z0-9_\-]+\.)*[a-z0-9_\-]+@([a-z0-9][a-z0-9\-]*[a-z0-9]\.)+[a-z]{2,4}$/i).test(email);
}