Use of the if() function

I hate to sound like a total dillweed, but I just can't figure out the if() function.

Here's my first attempt;
//-----------------------------------------------------------------------------
function Sub1Fortune() // This function subtracts one point from the current
// Fortune.
{
var iCurrFortune = Fortune.value;
var iNewFortune = 0;
iNewFortune = iCurrFortune - 1
if(iNewFortune < 0, 0, iNewFortune);
}
//-----------------------------------------------------------------------------

Didn't do a thing.

Then, thinking maybe I'd misunderstood the meaning of "Return" in the if() function syntax from the help document, I tried this;
//-----------------------------------------------------------------------------
function Sub1Fortune() // This function subtracts one point from the current
// Fortune.
{
var iCurrFortune = Fortune.value;
var iNewFortune = 0;
iReturnFortune = 0;
iNewFortune = iCurrFortune - 1
iReturnFortune = if(iNewFortune < 0, 0, iNewFortune);
return iReturnFortune;
}
//-----------------------------------------------------------------------------

This just gave me a syntax error on the if() line, which I figured it would.

Basically, all I want to do is subtract 1 from the current Fortune, unless that would result in a value less than 0, in which case it needs to remain 0. It seems this should be a simple thing.

Thanx for any assistance!