Database error while upgrading

[imnotaterrorist]

i just upgraded from 3.6.9 to 3.7 but when i get to the part that says go to www.xxxx.com/xxxx/install/upgrade.php i keep getting a data base error that says this

Database error in vBulletin :

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Access denied for user 'root'@'localhost' (using password: NO)
/home/tylerper/public_html/demonflicks/includes/class_core.php on line 311

MySQL Error   : 
Error Number  : 
Request Date  : Tuesday, April 29th 2008 @ 10:15:24 PM
Error Date    : Tuesday, April 29th 2008 @ 10:15:24 PM
Script        : http://tylerperroux.com/demonflicks/install/upgrade.php
Referrer      : 
IP Address    : 70.112.251.115
Username      : 
Classname     : vB_Database
MySQL Version :

any idea what im doing wrong and how i can fix it?