FPS1.3 Basic Walking/Running.

I don't really know the best way to articulate my question. I was doing ETeeskiTutorials on Basic Wallking/Running, and when I enter in the same code he did and hit play, my capsule goes up into the air ever so slightly and then as soon as I move my mouse it launces into infinite space upward never to be seen again... I don't understand why this is happening.

For more insight:
http://postimg.org/image/cpxjqxy2h/
http://postimg.org/image/ydmi1dygp/

What happens when I hit play notice capsule jumps up slightyly:
http://postimg.org/image/z4jtkwq7t/

And as soon as I move mouse notice how small the plane has become due to the fact that I am going up infinetly;
http://postimg.org/image/rd33mcm2h/

This is the PlayerMovementScript

Code (JavaScript):

1. var walkAcceleration : float = 5;
2. var cameraObject : GameObject;
3.  
4. function Update ()
5. {
6.     transform.rotation = Quaternion.Euler(0, cameraObject.GetComponent(MouseLookScript).currentYRotation, 0);
7. }

And this is the MouseLookScript

Code (JavaScript):

1. var lookSensitivity : float = 5;
2. @HideInInspector
3. var yRotation : float;
4. @HideInInspector
5. var xRotation : float;
6. @HideInInspector
7. var currentXRotation : float;
8. @HideInInspector
9. var currentYRotation : float;
10. @HideInInspector
11. var yRotationV : float;
12. @HideInInspector
13. var xRotationV : float;
14. var lookSmoothDamp : float = 0.1;
15. function Update ()
16. {
17.     yRotation += Input.GetAxis("Mouse X") * lookSensitivity;
18.     xRotation -= Input.GetAxis("Mouse Y") * lookSensitivity;
19.  
20.     xRotation = Mathf.Clamp(xRotation, -90, 90);
21.  
22.  
23.     currentXRotation = Mathf.SmoothDamp(currentXRotation, xRotation, xRotationV, lookSmoothDamp);
24.     currentYRotation = Mathf.SmoothDamp(currentYRotation, yRotation, yRotationV, lookSmoothDamp);
25.  
26.     transform.rotation = Quaternion.Euler(currentXRotation, currentYRotation, 0);
27. }