I came from Europe (Italy) and I want to go in Canada from the Usa but I want to stay more then a week they take my I 94 w?if yes and I want to return in the Usa they give me another I 94 w or can I ask a I 94?:)

You can enter US under visa waiver program and you can enter Canada from US, but returning back to US again after one week in Canada is impossible unless you can convince immigration officers why they should let you in...