What to wear to an interview?

I have an interview tomorrow for the position of switchboard operator at a hotel and I can't decide which way to go. Since it is (I presume) a "behind the scenes" position I first thought dress slacks and a blouse (I can't wear skirts or dresses for reasons which I won't go into) but then, since the hotel is a major luxury chain with alot of prestige I then thought business pants suit. Any thoughts?