install.php with Error establishing a database connection

Hello, I’m novice to WP and really need your help.When installing, I encountered an error ‘Error establishing a database connection’.Then after tried almost hundreds of times,it still stay still.
Are you sure you have the correct username and password?
Are you sure that you have typed the correct hostname?
Are you sure that the database server is running?
these three questions I have checked,just want to know what else operations I should try.

The page I need help with: [log in to see the link]