I am using 2 accelerometers connected to an arduino. The code below does not work.

> if((acc1 >= 20 && acc1 <= 40) && (acc2 >= 20 && acc2 <=40)) //If acc1 is between 20 and 40 AND if acc2 is between 20 and 40
>     {
>         digitalWrite(13, HIGH);
>     }

But, the following code does:

> if((acc1 >= 20 && acc1 <= 40)) //If acc1 is between 20 and 40
>     {
>         digitalWrite(13, HIGH);
>     }

Can anyone tell me why please?