error permission not permitted

[Najm-ul-Abideen]

Thanks,

Basically I was doing this on:

http://gifs.zxq.net

As you can see on the site I am keeping images, and I am having cautions to avoid porn or other abuse images uploaded by the users. Therefore I made a script to list down all and delete. But when I submit the page it gives me the error of "permission denied in xyz page", therefore I changed the chmod("filename",0777) then execute but now it gave me the error permission not permitted in this situation what I suppose to do.

And I also chown("filename","user") but it is giving error that unable to find uid "user" 1st I have used my username and then the ftp username but on both I got this

please help me as soon as possible as I have to complete this, its complete just this tasks remaining as during upload I am in same situation which is basic for my site.

Thanks,

Najm.