some PHP basic security

["Vikas Singhal" <vikas.programmer () gmail com>]

Hi List!!
This is a basic question i guess but it is important. I am creating a
website in which i want to provide
login restriction to download or upload any files. but i am getting some
difficulty
1. after logout if someone goes back and try to download the file he can do
so.
2. i can't able to clear POST data. how to do that
3. i want to make the uploads area secure. i gave write permission to others
which i think is not secure.

there  are many questions around here but try to give atleast one ans.

--
- Vikas Singhal

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