🚀 go-pugleaf

I have descendant of JFrame. It's contentPane is set to desktopPane.
I have this code:
      fmSQL = new IFmSQL( conn );
      fmSQL.setVisible( true );
      desktop.add( fmSQL );
      try
          {
          fmSQL.setSelected( true );
          }
      catch(java.beans.PropertyVetoException exc) {}
      }

fmSQL is descendat of JInternalFrame.
it's constructor looks like this
  public IFmSQL( java.sql.Connection conn )
  {
    super( "fgf",true,true,true,true );
    this.conn = conn;
    try
    {
      jbInit();
    }
    catch(Exception e)
    {
      e.printStackTrace();
    }
  }

And after this nothing happens. How can I display internal frames? Where's
the bug?

thanks