Can't save html changes

[Bobadventures]

Hi. I just went into ftp to change a bit of code on my archive page, and when I hit the save button, I got this error message:

Warning: ftp_put() [function.ftp-put]: Can't open that file: Permission denied in /home/space/siteadmin/public_html/net2ftp/includes/filesystem.inc.php on line 684
Back (accesskey b) Save (accesskey s) File: /public_html/stories.html
Status: This file could not be saved

Any idea what's going on?