How can I turn my cube object to the direction it is traveling?

I have tried many different options with Quaternions and what not, but all I want is for my cube to face the way it is sliding. It can’t be this hard…

This is the move function I have in place:

private void FixedUpdate ()
{
// Adjust the rigidbodies position and orientation in FixedUpdate.
Move ();

}

private void Move()
{
	// Move the character with vectors
	Vector3 movement = transform.forward * cube_VerticalMovement * cube_Speed *Time.deltaTime;
	Vector3 movement2 = transform.right * cube_HorizontalMovement * cube_Speed *Time.deltaTime;
	Vector3 MoveVector = movement + movement2;

	cube_Rigidbody.MovePosition (cube_Rigidbody.position + MoveVector);

	// Turn the character in the direction of movement

}

Thanks. I did that and it set the forward vector into the ground for some reason.This in turn kills the movement code I have in place. Still working on it.