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Again, look at that stack trace. It's telling you exactly what line the error is on: Allawt.paint(Allawt.java:106)

What line is that? Have you used print statements or a debugger to figure out the...

Look at line 36. Something is null there. Use print statements (or better yet, a debugger) to figure out what is null.

Hint: Do you mean to set the same variable (b1) 6 different times?