UIElement.ToggleVisibility C# (CSharp) Method

    public void ToggleVisibility()
    {
        if (!visible)
        {
            make_visible();
        }
        else
        {
            make_invisible();
        }
    }

 void Update()
 {
     if (Input.GetKeyUp(KeyCode.F1))
     {
         ui_element.ToggleVisibility();
     }
 }