Pythagorean Theorem Program - Code Isn't Working When Written In OOP Style

I'm attempting to make a simple Pythagorean Theorem program (A squared + B squared = C squared) but am running into problems when I write it as object oriented. The darn thing works when written as a simple process, but that isn't Java now is it? Here's the simple:

public class PythagoreanTheorem extends ConsoleProgram {
public void run() {
println ("Finding C from A and B.");
double a1 = readDouble("Input A: ");
double b1 = readDouble("Input B: ");
double aSq = (a1*a1);
double bSq = (b1*b1);
double cSq = (aSq + bSq);
double c = Math.sqrt(cSq);
println ("C = " + c);

[code]....