Multiple currentframes

im using the following code on a button in a movieclip:

if (_root._currentframe == 84) {
trace (“true”);
} else {
trace (“false”);
}

but i want it to test if the current frame is anyframe between 40 and 138.
i tried, 40 or 41 or 42 and so on… but that didnt work. can anybody help?

Thnx,
Brendan Smith