Flash - Output The Text For "future" From Function Year()?

Why does this program always output the text for "future" from function year()? In this case, with b+c equaling 56, var year should fall under (b+c) > 0 && (b+c) < 1000) and return "roman", but it instead returns "future"...I got this to successfully work if I add this:

var period:String = (year(b,c));

and in my body function, make the conditionals check the period. For example

if (period == "future")

but I don't understand why I need to do this. I am returning a string, why do I have to set another variable? There is no compiler errors so clearly its not syntactical?

var a:String = "Tim";
var b:int = 50; //CHANGE TO ANY INT YOU WANT
var c:int = 6; //CHANGE TO ANY INT YOU WANT
var d:String = "Kyle";
var sum:int = b+c;

[code]....