How can I take into account the Y axis when AddingForce?

Hey all I have a problem on how to addForce in the correct direction. First let me Explain what’s going on in the game:
We are in space…
therefore, to me it would make sense to use Addforce (considering the old law "an object in motion tends to stay in motion(unless interfered with)). //Yes I’m kind of a geek// lol but uh…

The problem here in lies, when the ship flips a 180 the “up Key” still adds force as if we were at 0 on the Y axis.
what could I add to this to help it take the Y axis into account?

Thanks in advance.

void FixedUpdate(){
//This is for ship movement (physics)//
float moveHorizontal = Input.GetAxis (“Horizontal”);
float moveVertical = Input.GetAxis (“Vertical”);

Vector3 movement = new Vector3(moveHorizontal, 0f, moveVertical);
RB = GetComponent ();
RB.AddForce ((speedCurrent * movement * Time.deltaTime) * 10);
Vector3 yPos = new Vector3 (transform.position.x, 0, transform.position.z);
transform.position = yPos;

}

//Please note yPos is a temporary y position holder until I program Y movement.

You can use Transform.up and the like to get the vectors in local space.

Also, please use Code Tags

The Ship was still moving backwards but since I will need a crosshair anyway I just attached the GameObj for it to the front of the ship and told it to follow just follow that lol

how did it take me this long to figure that out???
at least this way I can hook my mouse to the crosshair for control and use a quaternion to rotate the ship according to speed so it can do loops