Calculations in roo.

[bluecolon]

I'm newbie in roo. now i can create a prototype. but i don't know how to handles computations in roo.
e.g
I have three int fields a, b and c.
if set input
a = 3
b=12
then
c= a+b = 15 << how to sum a and b to this field. edit code in java file or ...

It's very simply program. that to be easy if i known how to creates computation function in roo.
Thanks in advanced

[MiB]

Just use Java, unless you have very specific needs to do computations in the browser.