Answered
Ok,
I understand how to use something like Excel for performing conditional calculations, but my first foray into this Java stuff is like Greek to me.
Here's the script I inserted into a field calculation.
var f = getField("csd");
if (f < 0.5){event.value = 0}
else {event.value = ((f.value - 1) * 40) + (45)};
When I type the value 1 (or more) into the "csd" field, the calculation is correct.
When I type 0 into the "csd" field, the event value comes out 5, not 0 as I would like.
I know this is extremely basic, but I gave up trying to understand the Java script info since it "hurts my head".