Axis : top down shooter help

i have a spaceship and i want to make a plane that runs horizontal with the ship. then i would like to get the mouse position along that plane and have the front of the ship aim towards that point. any suggestions or ideas. thank you

This script moves the ship in the velocity defined by ‘speed’, and when you click anywhere in the screen the ship turns gently (and horizontally) to the point clicked in ‘turnTime’ seconds.

Add the prefab Standard Assets/Character Controllers/First Person Controller to your scene and add the script below to it. Disable or delete the First Person Controller’s 3 original scripts (MouseLook, FPSInputController and CharacterMotor). Be aware: there’s another MouseLook script hidden in the Main Camera - find and destroy it too!

That’s my script:

var speed:float = 6; // movement speed
var turnTime:float = 2;  // time taken to turn to the new direction
private var controller:CharacterController;

function Start(){

	controller = GetComponent(CharacterController);
}

private var newDir:Vector3;
private var oldDir:Vector3;
private var t:float = 0;

function Update(){

	if (Input.GetMouseButtonDown(0)){
		var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition);
		newDir = ray.direction;
		newDir.y = 0;
		t = turnTime;
		oldDir = transform.forward;
	}
	if (t>0){
		transform.forward = newDir*(1-t/turnTime)+oldDir*t/turnTime;
		t -= Time.deltaTime;
	}	
	controller.Move(transform.forward*Time.deltaTime*speed);
}

Have fun!