Create bounded movement

Hello, to everyone.
I am new in Unity and I am trying to create a simple game in which the player will fire bullets in the direction of the mouse pointer.
My problem is that I can not set bounds for the movement of my player, I checked unity manual for bounds but to be honest I couldn’t understand. I have put an if condition in which if the x becomes equal to 90 then the object should be placed at x=89. But it doesn’t work. Can you please give a help or hint with this??

Here is my code in C#

**using UnityEngine;
using System.Collections;
public class player : MonoBehaviour {
public float speed = 10.0F;
public float rotationSpeed = 100.0F;
Vector3 pos = new Vector3(0,0,0);

// Use this for initialization
void Start () {
// Update is called once per frame
void Update () {
  	float translation = Input.GetAxis("Vertical") * speed;
    float rotation = Input.GetAxis("Horizontal") * rotationSpeed;
    translation *= Time.deltaTime;
    rotation *= Time.deltaTime;
    transform.Translate(0, 0, translation);
    transform.Rotate(0, rotation, 0);
	pos = transform.position ;		
	    if(f.GetMouseButtonDown(0))	{
		Plane zeroPlane = new Plane( Vector3.up, );
		Ray ray = Camera.main.ScreenPointToRay( Input.mousePosition );
		float distance;
		if (zeroPlane.Raycast(ray, out distance))
			Vector3 outputPosition = ray.origin + ray.direction * distance;
			GameObject go1 = (GameObject)Instantiate(GameObject.Find("bullet"), pos, Quaternion.identity); 
			go1.rigidbody.AddForce( outputPosition * 10, ForceMode.Impulse);
	if (pos.x ==90)

I found the solution

Just put this line of code

transform.position = new Vector3(Mathf.Clamp(transform.position.x, -90.0F, 90.0F), 0, Mathf.Clamp(transform.position.z, -36.0F, 36.0F));

I apologize for the inconvenience