function a_times_b(form) {
a = eval(form.a.value);
b = eval(form.b.value);
c = 1 / 450240 * a * b * b;
form.c.value = c;
}

function c_div_b(form) {
c = eval(form.c.value);
b = eval(form.b.value);
a = c / (b * b);
form.a.value = a * 450240;
}

function c_div_a(form) {
c = eval(form.c.value);
a = eval(form.a.value);
b = c / (1 / 2 * a);
form.b.value = Math.sqrt(c / (1 / 450240 * a));
}

function y_times_x(form) {
w = eval(form.w.value);
x = eval(form.x.value);
y = eval(form.y.value);
z = ( w * 100 ) / ( y * x *1.047 );
form.z.value = z;
}

function y_times_z(form) {
z = eval(form.z.value);
y = eval(form.y.value);
x = eval(form.x.value);
w = y * z * x * 1.047;
form.w.value = w / 100;
}

function w_div_y(form) {
z = eval(form.z.value);
y = eval(form.y.value);
w = eval(form.w.value);
x = ( w * 100 ) / ( z * y * 1.047 );
form.x.value = x;
}

function w_div_z(form) {
z = eval(form.z.value);
x = eval(form.x.value);
w = eval(form.w.value);
y = ( w * 100 ) / ( z * x * 1.047 );
form.y.value = y;
}