Ok its a simple tut on showing you how to make a different background for the trade, bank and shop interface 
Go into Class 30_sub2_sub1_sub1
And under one of your sprites add this:
Code:
else if(s.startsWith("tradebacking"))
{
try
{
Image image21 = Toolkit.getDefaultToolkit().getImage("/Sprites/tradebacking 0.gif");
anIntArray1439 = new int[anInt1440 * anInt1441]; // H0rn :)
PixelGrabber pixelgrabber21 = new PixelGrabber(image21, 0, 0, anInt1440, anInt1441, anIntArray1439, 0, anInt1440);
pixelgrabber21.grabPixels();
}
catch(Exception exception21)
{
System.out.println(exception21);
}
}

Thanks H0rn