cannot upload file via http

[pkagan at videotron.ca]

Hi I am trying and have been trying in multiple ways to be able to upload a
file with php programming and http but for some reason it is not able to
write. I know this because no write takes place. This could be with a
wordpress or any content management system as well as my own php code. I
went ahead and changed the user permissions to 755 and the ownership to www.
What could be the  problem?