Mibew Messenger (Open Web Messenger): Installation Problems

I’m trying to install supporting software Mibew Messenger (also known as Open Web Messenger), an open-source live support application written in PHP and MySQL. Their site is -> www.mibew.org

I did all the required settings, and I created the database.
But when I try to install the program, I get the following error message:

Correct the mistakes:
Could not connect. Please check server settings in config.php. Error: Access denied for user ‘milena’@‘mizar.dreamhost.com’ (using password: YES)

I tried to change the permissions of the mySQL user, so that he could access the database from my IP address. But it did not work.