Include files in php showing error

I am having a folder called "db". where it contains 3 files which calls from the mail file "con开发者_如何学编程nect.php".

I created a new file in root directory and wrote a function

include "db/connect.php");
echo $connstring;

Here I am not getting any output, the $connstring is defined in another file in "db" folder named as "config.php" which is included in beginning of the "connect.php"

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You have written wrong code for include function.

You should try this,

include ("db/connect.php");
echo $connstring;

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I exactly was looking hot to include the files from different directories correctly.

This is how I got the code to achieve this from one of the project on Zend.

set_include_path( dirname(dirname(dirname(dirname(FILE)))) . DIRECTORY_SEPARATOR . 'library' );