Tank Turret move on XAxis by Mouse XAxis

i am on day 4 of using Unity/Blender, i copy and paste a lot from tutorial on youtube

my game so far Filesharing.com - Send & Share Large Files Online - Up to 1GB Free Filehosting

i have try using the script form this video

but i have more the one camera

only one the came close was this one

var rotationSpeed = 100.0;

function Update () {
var zdir = Input.GetAxis("Mouse X");
transform.Rotate(zdir * rotationSpeed * Time.deltaTime, 0, 0);

but that moves the turret up and down, not left and right

looked a loot on this page to, but most use keys to move it or MouseDrag or ray

only thing i am looking for is a script that i can put on my turret that makes it move, right and left when i move my mouse right and left

or and noob tutorial

i made it work, i made a cude put the script on it flip it 90 on ZAxis and put my tank top in it, and than put all back ind to my tank

now i only need to find some limit script