From: Luke Oliver Palmer <lop@acpub.duke.edu>
  To  : 
  Date: Tue, 13 Apr 1999 22:57:42 -0400

Re: URL exceptions

by the way, this seems to be a common problem:

after you've gotten everything working, whatever you have written to add
images (this does not heppen with balls) only sometimes works.  that is, every
other click or so does not produce a new ball, and remove appears to have the
same problem.  this is because there is a typo in the original MyApplet.java;
for the second image, images is spelled 'imagse.'  an exception is not thrown
when it is loaded, so there is a spot in the image array with an invalid
image.  when your program tries to create a new ball using this image, nothing
happens.

just thought i'd offer the tip, because it took me about an hour to figure out
why my code didn't work every time...

-luke