need help with wordpress error..

hi ..i changed my wordpress hosting from one server to another...
am now getting error establishing database connection..

here is what i did...
1.downloaded all the wordpress files from original hosting
2.changed nameservers to new hosting.
3.created an add on domain on new hosting.
4.uploaded wordpress files in this new add domain
4.created a db and associated a user to it in new hosting.
5.exported the old database and saved it on my hard disk.
6.imported the database into the new hosting for the newly created db
7.open the wp-config file and changed the dbname username and password as it was for new db in my new hosting.
8.opened the site....getting "error establishing database connection"

tried:
checked the wp-config.php ..the info is correct.. even changed password again and checked..

repaired wp_options table for the new db..still getting the error..


my site was working fine just after changing the hosting but it gave error next day... i guess it was working fine the previous day because of cookies which i deleted the next day before checking my site..

i still have access to my old hosting...

is there any other solution..

can i restore back to original hosting...