How can I remove the gradient background & border from an ImageIcon?

Question

Problem1: Hey, I have a program that randomly displays a stop sign that I'm supposed to click on as fast as I can. And I created a gif with the stop sign, with it's background transparent. But when I added it to my application using an ImageIcon, whatever's supposed to be transparent in the gif is shown up as a gradient. There's also a border around the ImageIcon. Is there any way to get rid of these? Thanks
Problem 2: I also have a background for my entire application, but it stays the same size no matter if I maximize the application or run it on a different screen size. Is there any way to scale a background (it's animated), to the full screen?
Thanks again! It's for a project due tomorrow. I'm doing final touches.
Here's some of my code. It's really long, so I took out what I think is related. JButton stopSign1 = new JButton();
this.getContentPane().add(stopSign1,null);
         ImageIcon stopSign = new ImageIcon("Dead_End.gif");
         stopSign1.setBounds(new Rectangle(randomX, randomY, 150, 150));
         stopSign1.setIcon(stopSign);
         stopSign1.setVisible(false);

Answer 1

Try stopSign1.setBorder(null);
stopSign1.setOpaque(false);Also, in future, post Swing questions in the Swing forum.