GCD Javascript Algorithm

gcd.js

var a, b, u, g, x, y;
u = 1;
x = 0;
a = 527; // Set here
b = 1258; // Set here
g = a;
y = b;
if (b == 0) { // For part d
    console.log("Division by zero error. Set b > 0.");
    return;
}
do {
    var t = g % y;
    var q = (g-t) / y;
    var s = u - q*x;
    u = x;
    g = y;
    x = s;
    y = t;
}
while (y > 0);
var v = (g-a*u)/b;
if (u < 0) { // for part e
    u = u + b/g;
    v = v - a/g;
}
console.log(g,u,v);