After Chaning my host my website shows "Error establishing a database connection

WordPress Experts,
I have recently changed my hosting
now my domain is shwoing “Error establishing a database connection”
Now what to do ! First time i have changed my host and what only thing i had done was uploading and downloading data from old to new host ! . My New host in Ipage

[mod: closed as duplicate of https://www.ads-software.com/support/topic/after-chaning-my-host-my-website-shows-error-establishing-a-database-connection-1?replies=4 ]