Forum Blocks - Help

[Hiro]

I want to put a PHP form in a forum blocks bit (the right side on vbulletin 4.0.x), and under the form I want to echo a cookie.

Basically, the current code I have is:

PHP Code:

$output .= '<form action="http://www.path.com/script.php" method="post">
<input type="text" name="city">
<input type="submit" name="submitcity" value="Search">
</form>';

$output .= $_COOKIE['citysearch'];

return $output; 


This works fine... it submits the form to the script.php, sets the cookie as the entered city and then echos the COOKIE on the block below the form.

I'm having problems with the blocks caching system, as if I do a new search and the cookie changes, the previous result is still cached in the block.

How can I work around this to get the block performing in real time and not cached?