Congratulations on asking completely the wrong question.
You want to know how to connect to a database on godaddy.com.
what should i write
in place of "localhost" "mysql_user" "mysql_password"
Don't know anything about godaddy but this is what you need generically
"localhost" the address of the database ie dbnumber.godaddy.com
"mysql_user" a user name with authority to access the database
"mysql_password" The password for the database applicable to said user
These should be in quotes as in your example
and what would be database name?
I can't believe you are asking that.
But then I don't know how godaddy works
Good luck anyway