Are you sure its a week old? What are you housing it in? If it doesnt eat today, wait 3 days, and then put a pinkie in with it and leave the snake for a few hours in the dark.
I'd personally leave it alone for a week, with the exeption of changing its water daily. That way it can settle in and get used to its new surroundings and smells. Then I'd try feeding again in a week.
in your other thread you said you have had it 2 days, but its a week old, so you got it when it was only 5 days old??!? most sellers will not let their snakes go until they have had between 3 and 5 feeds.
9.11 Cornsnakes 1.1 Hogg island boas 1.0 Dwarf Burmese python