exclude duplicate files

[marvell]

Hello. I'm trying to download the forum (all sections and posts are only on the first page of each topic), but I'm running into a cross-referencing problem on the pages.
For example:
/forum/viewforum.php?f=1 -- this page contains a link to /forum/index.php and your program downloads a copy of already downloaded sections again forum.
Example 2:

/forum/viewforum.php?f=1&start=50
/forum/viewforum.php?f=1&start=100
/forum/viewforum.php?f=1&start=150
"start" -- indicates the page number of the directory (like page 1, page 2, page 3, etc). Each catalog page includes a link to the previous page. Your program creates a complete copy of the site with each successive page.

How can I configure the program so that it does not download duplicates of already existing sections and topics on the forum?
How to prevent repeated download of the same file on different pages?

[szetakyu]

+1