function validate_form(minlength) {
    var user = validate_username();
    var pass = validate_password(minlength);

    return validate_confirm() && pass && user;
}

function validate_confirm() {
    var password = document.getElementById("newpassword");
    var confirm = document.getElementById("confirm_password");

    if (password.value != confirm.value) {
        confirm.classList.add("errorinput");
        document.getElementById("confirm-msg").classList.add("errormsg");
        return false;
    }

    confirm.classList.remove("errorinput");
    document.getElementById("confirm-msg").classList.remove("errormsg");

    return true;
}

function validate_username() {
    var username = document.getElementById("username");
    var forbidden = /[*?!'\^+%\&/()=}{\$#;,\\"]+/;

    if (username.value.length > 64 || forbidden.test(username.value) == true)
    {
        document.getElementById("username-msg").classList.add("errormsg");
        username.classList.add("errorinput");
        return false;
    }

    document.getElementById("username-msg").classList.remove("errormsg");
    username.classList.remove("errorinput");
    return true;
}

function validate_password(minlength) {
    // Did the checks pass ?
    var status = true;
    // Target element
    var password = document.getElementById("newpassword");
    // Check the length
    if (password.value.length < minlength)
    {
        status = false;
        document.getElementById("minlen").classList.add("errormsg");
    }
    else
        document.getElementById("minlen").classList.remove("errormsg");
    // Look for a digit
    if (/.*\d/.test(password.value) != true) {
        status = false;
        document.getElementById("digit").classList.add("errormsg");
    }
    else
        document.getElementById("digit").classList.remove("errormsg");
    // Look for a lowercase char
    if (/.*[a-z]/.test(password.value) != true) {
        status = false;
        document.getElementById("lower").classList.add("errormsg");
    }
    else
        document.getElementById("lower").classList.remove("errormsg");
    // Look for an uppercase char
    if (/.*[A-Z]/.test(password.value) != true) {
        status = false;
        document.getElementById("upper").classList.add("errormsg");
    }
    else
        document.getElementById("upper").classList.remove("errormsg");
    // Change the color of the inputbox
    if (status == false)
    {
        password.classList.add("errorinput");
    }
    else
        password.classList.remove("errorinput");

    return status;
}