I have an application in which there is a functionality to upload files to server setup as localhost. It works fine on a Windows and an OpenSuSE machine.

But, I face HTTP I/O Error while uploading it on a Ubuntu machine. It seems as if I am not setting permissions to /var/www/myapp, right.

[owner,group of /var/www/myapp/* ] = [usman,www-data]
Permissions of /var/www/myapp/* = 755 (tried 777 and 775 too but invain)

Apache server is being run by www-data

The file I upload does not find it's way even to /tmp

App is actually based on Actionscript+PHP. Upload.php and all other source code is residing in /var/www/myapp

By the way, I have also made usman member of www-data by amending /etc/group although it wasn't necessary, i think.

How can I give write access to my server for writing files to /var/www/myapp?