title: creating movable panel inside frame in java
body: <p>I am trying to build simple application, just for knowledge. I would like to build something like option box. From menu when user clicks any option(like preferences) then a movable panel appears.</p>
  
  <p>JFrame contains menu bar, and suitable menu item on clicked should cause a JPanel to appear.</p>
  
  <p>I got no idea to proceed. Can anyone help me?</p>