problem with header function

[slackman]

i get php open-source for export SQL format from my database.
i test that it's work fine, but i use script include with my program(php) not working and found problem with header function

1. if i insert session_start(); and session_is_registered($test); for check user login first, script for export SQL format not working
2. i want to check user login first for export database(security)
3. help me!!
4. script for export database to SQL format that in attachment file(please to fix it for working with session_start(); and session_is_registered().