title: loading image on a panel
body: <p>First I load an image in a picturebox. Then I measure the areas in it and create a new picture. Now I want to load the image in a panel and draw a line by mouse.
  I added to my form:</p>
  
  <pre><code>private Image imag;
  </code></pre>
  
  <p>I also added to my project:</p>
  
  <pre><code>private void drawP_Paint(object sender, PaintEventArgs e)
  {
      Graphics g = drawP.CreateGraphics(); 
      g.DrawImage(imag, new Point(0,0));
  }
  </code></pre>
  
  <p>I set the image in a function:</p>
  
  <pre><code>imag = (Image)bm;     
  // or
  imag = picturebox1.Image; // the made picture   
  drawP.Invalidate();
  </code></pre>
  
  <p>But nothing appears when running the project.</p>