function formDisabled(v){
    loginDisabled(v)
    loginCancelButton.disabled = v
    loginUsername.disabled = v
    loginPassword.disabled = v
    if(v){
        checkmarkContainer.setAttribute('disabled', v)
    } else {
        checkmarkContainer.removeAttribute('disabled')
    }
    loginRememberOption.disabled = v
}
Enable or disable login form.

@param {boolean} v True to enable, false to disable.