If your comments are stored in a file:
-You could make a copy of your file (so you never lose your comments)
-Only display the first 20 comments (using a counter)
-Copy the rest of the file (remaining comments) to another file
-rename this file to same as before.
- create your link to the next 20.
-lather, rinse, repeat...until EOF
Give me an idea of how your comments are stored, and I could give you a few snippets to help!
Good luck,
Andre