I followed some advices to learn Slick2D and when I started doing the "SimpleGame" I got my first error. Does anyone have any idea of what is it and how to fix?

Sun Dec 26 23:09:12 GMT-03:00 2010 INFO:Slick Build #274
Sun Dec 26 23:09:12 GMT-03:00 2010 INFO:LWJGL Version: 2.0b1
Sun Dec 26 23:09:12 GMT-03:00 2010 INFO:OriginalDisplayMode: 1024 x 768 x 16 @60Hz
Sun Dec 26 23:09:12 GMT-03:00 2010 INFO:TargetDisplayMode: 800 x 600 x 0 @0Hz
Sun Dec 26 23:09:12 GMT-03:00 2010 ERROR:Could not find a valid pixel format
org.lwjgl.LWJGLException: Could not find a valid pixel format
 at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)
 at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)
 at org.lwjgl.opengl.WindowsDisplayPeerInfo.initDC(WindowsDisplayPeerInfo.java:54)
 at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:158)
 at org.lwjgl.opengl.Display.createWindow(Display.java:299)
 at org.lwjgl.opengl.Display.create(Display.java:848)
 at org.lwjgl.opengl.Display.create(Display.java:800)
 at org.newdawn.slick.AppGameContainer.tryCreateDisplay(AppGameContainer.java:299)
 at org.newdawn.slick.AppGameContainer.access$000(AppGameContainer.java:34)
 at org.newdawn.slick.AppGameContainer$2.run(AppGameContainer.java:364)
 at java.security.AccessController.doPrivileged(Native Method)
 at org.newdawn.slick.AppGameContainer.setup(AppGameContainer.java:345)
 at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:314)
 at SimpleGame.main(SimpleGame.java:38)
Exception in thread "main" org.newdawn.slick.SlickException: Failed to initialise the LWJGL display
 at org.newdawn.slick.AppGameContainer.setup(AppGameContainer.java:375)
 at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:314)
 at SimpleGame.main(SimpleGame.java:38)