how to set mysql for new software

I have new classifieds software that uses mysql database. I have
loaded the software into my domain host but connot seems make mysql
setups that works. When i go to my site on the net I et error Warning:
mysql_connect() [function.mysql-connect]: Access denied for user
'db_username'@'localhost' (using password: YES) in /home/buyrentp/
public_html/conn.php on line 27
Access denied for user 'db_username'@'localhost' (using password: YES)

What do i do to set it up in cpanel and how does the new software
connect to the database? Should I load the software after I do the
database and if so how will it connect to it. I have an older database
that was made for there too but have not deleted it, do I need to?
George

gf DeleteThis @naturalproperties.com wrote:
> I have new classifieds software that uses mysql database. I have
> loaded the software into my domain host but connot seems make mysql
> setups that works. When i go to my site on the net I et error Warning:
> mysql_connect() [function.mysql-connect]: Access denied for user
> 'db_username'@'localhost' (using password: YES) in /home/buyrentp/
> public_html/conn.php on line 27
> Access denied for user 'db_username'@'localhost' (using password: YES)
>
> What do i do to set it up in cpanel and how does the new software
> connect to the database? Should I load the software after I do the
> database and if so how will it connect to it. I have an older database
> that was made for there too but have not deleted it, do I need to?
> George

did you create a database, and a user, then set the user to use the db and
permisson all?