Make camera rotate don't stop

Guys, I need your help.

I wan’t to make the main camera to rotate around the scene. Just rotate, not moving or following something.

The code below worked and I have an exported apk where it works. But somehow when I reopened the Unity it doesn’t work anymore.

function Update () {
	transform.Rotate(Vector3.down * Time.deltaTime * rotationSpeed);
}

This code only makes the camera rotate for 1 frame. I want it to never stop.

What am I missing here?

Create object in the center and attach Camera object(on the distance) and the Script on it.

void Update () {
transform.localRotation *= Quaternion.Euler(0, needAngularSpeed * Time.deltaTime, 0);
}