function userdetailsub() {
    
    // Verify password...
    var upass = document.userdetailform.dpassword.value;
    if (upass.length<6 || upass.length>20) {
        alert("The password should be between 6 and 20 characters.");
        return false;
    }
    
    // Verify nickname...
    var unick = document.userdetailform.nickname.value;
    if (unick.length<5 || unick.length>30) {
        alert("The nickname should be between 5 and 30 characters.");
        return false;
    }
    
    return true;
}