I have the Beginning Java 2 (JDK 1.3 ed) book and it tells how to write to 
zip files but I want to know how to append to a zip file.  When I do it I 
can add as many files to the zip file I want the first time through but if 
I run the program again and try to add to the same zip file it erases what 
is in the file and adds the new stuff.