Database error - undefined function mysql_connect()

[eluser]Mauricio de Abreu Antunes[/eluser]
I can not use mysql_connect.
It's strange because yesterday i was using CI and i posted another problems here.
Is missing any MySQL lib?

[EDIT]

I'm debugging my configs in my database.config with manual SQL functions like mysql_connect.

[eluser]solid9[/eluser]
Why do you still use mysql_connect()?

Isn't everything is already in /config/database.php ?

[eluser]Mauricio de Abreu Antunes[/eluser]
How i said, my CI is not getting connection with MySQL.
So i tried to debug my connection. And i used mysql_connect to debug.