Error establishing a database connection- Please help

Help, I don?′t know what happened or how to fix this. I created a blog (www.andes-natural.com) in cpanel through fantastico last week and now it gives me this error message.
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This either means that the username and password information in your wp-config.php file is incorrect or we can’t contact the database server at localhost. This could mean your host’s database server is down.

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?
If you’re unsure what these terms mean you should probably contact your host. If you still need help you can always visit the WordPress Support Forums.
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I hadn?′t changed anything. What does this mean? What do I do?