Internal server error 500

[Smarty]

After uccessfull installation, I get above mentioned error when trying to enter admin user/password.
The error log points to a mysql db connect error : database blah_blah not found in installscj.php on line so and so.
Is it because i entered database name wrong (blah_blah instead of just blah) or could it be that i am running script from within public_html and not root folder?
Thanks for any advise.

[admin]

If you believe it's due to wrong DB name - just reinstall it. It takes few minutes.