Issue with AJAX/PHP/Apache data transmission and file permissions

I'm doing some analysis on user keystroke patterns for a biometrics-related prototype that I'm building. I'm having an issue where I pass variables via POST to another webpage, and that webpage calls a script that writes to the local server in a directory based on the data that's passed to it.

My prototype is simple: the user types some data into a text form, the keystrokes are collected, the user clicks submit at the end of the task, and that data is sent off to the server to be analyzed. However, PHP refuses to write to the directory specified via the web. If I go into the command-line PHP, it works. I even tried changing POST to GET in insertData, and passing in the data manually.

Here are a few things I think could be wrong:

1. My AJAX is wrong. It worked locally, but doesn't work on the web. However, I could have inadvertently changed something, and that's the source of this issue.
2. My file permissions for apache are incorrect. It's odd, though, because Apache owns the folder/file in question. SELinux is disabled, so that's one thing off of the list. I even tried chmod 777 on the folders in question, to no avail.
3. There's a directive in httpd.conf that I'm missin开发者_开发百科g, and apache is just not allowing web writes.

Server information:

CentOS 5 Apache2.2 PHP 5.3.6

Here is the source code for clarification. Assume all site names et al are correct.

1. http://jyaworski.pastebin.us/2799 GatherData.php

2. http://jyaworski.pastebin.us/2800 GatherData.js

3. htt://jyaworski.pastebin.us/2801 //sorry. SO won't let newbies post more than 2 links. Add a "p" to http InsertData.php

Thank you in advance; this issue has been plaguing me for some time.

Apache probably doesn't have write permissions on ".". Try putting it in /tmp and see if that fixes your problem. If so leave it there or add write permissions for apache in the directory you're trying to save the data to.

$dir = '/tmp/userdata/'.$id.'/';