title: C++ Builder paintbox, do not know how to use
body: <p>I would like to draw lines on paint box component which I put on the form.</p>
  <p>My questions are:</p>
  <ol>
  <li><p>In which func to implement it? am I should do it on FormPaint func or maybe on FormShow?</p>
  </li>
  <li><p>What paint box allow me to do? what is the power of paint box?</p>
  </li>
  </ol>