Guitar strings on a mandolin.

Question

I have an inexpensive, but playable A-style mandolin with standard gauge strings. What I'd like to do is tune it like the top 4 strings of a guitar (D,G, B, E - low to high). I've tried using guitar tuning already, but the strings are either way too lose or too tight. What gauge strings do I need? I don't want to damage the neck or break strings.
Any help will be greatly appreciated.