$umaxposts variable?

i'm looking in member.php and i try to understand from where is called from $umaxposts:

PHP Code:

$DB_site->query("UPDATE user SET maxposts='".addslashes($umaxposts)."' WHERE userid='$bbuserinfo[userid]'"); 

can you explain what it does that [high]$umaxposts[/high] variable?
thanks.

[Admin]

$umaxposts comes from the modifyoptions template (a form). It determines how many posts a user wants to see per page.

[TECK]

thanks firefly.