This is my code, Dont worry read it and help me, it wont take more than 2 minutes 
using UnityEngine;
using System.Collections;
public class characterScript : MonoBehaviour
{
//references
public float SwitchingSpeed;
public float ForwardSpeed;
public int HowFarToGo;
private bool OnLeft;
private bool OnRight;
private bool IsSwitching;
private int counter;
private bool ALTERNATOR, LeftOrRight;
private CharacterController controller;
private string activeAnimation;
// move variables
public float runSpeed = 8.0f;
public static float hero_z_position;
void Start ()
{
ALTERNATOR = true;
OnRight = true;
controller = gameObject.GetComponent<CharacterController>();
}
void Update ()
{
hero_z_position = transform.position.z;
controller.Move(transform.forward * 8f * Time.deltaTime);
animation.CrossFade("Run",0.0f);
if (Input.GetMouseButton(1) !IsSwitching){
IsSwitching = true;
ALTERNATOR = !ALTERNATOR;
LeftOrRight = ALTERNATOR;
Debug.Log(LeftOrRight);
StartCoroutine(SwitchLanes());}
}
private IEnumerator SwitchLanes ()
{
//if (IsSwitching)
// yield return null;
//IsSwitching = true;
while (counter < HowFarToGo)
{
counter++;
int directionSelector = OnRight ? 1 : -1;
// why my soldier is not moving left,right ??
if(LeftOrRight == true){
//Debug.Log("going left.."+LeftOrRight);
//controller.Move(directionSelector*transform.right * SwitchingSpeed * Time.deltaTime);
Vector3 pos = transform.position;
pos.x = Mathf.Clamp(pos.x,2.0f,2.0f);
transform.position = pos;
}
if(LeftOrRight == false){
//Debug.Log("entered");
//controller.Move(directionSelector*transform.right * (-SwitchingSpeed) * Time.deltaTime);
Vector3 pos = transform.position;
pos.x = Mathf.Clamp(pos.x,-2.0f,-2.0f);
transform.position = pos;
}
//controller.Move(directionSelector*transform.right * SwitchingSpeed * Time.deltaTime);
//animation.CrossFade("RunJump", 0.0f);
yield return new WaitForEndOfFrame();
}
counter = 0;
IsSwitching = false;
}
//Update is called once per frame
}
In this code i used this code of line to move my player from left to right and right to left [see line 62 and 70 above]
Problem:: The x position does not remain same, it changes like x=3.1 will change to x=2.9 , I dont know how to tackle with this solution
//controller.Move(directionSelector*transform.right * SwitchingSpeed * Time.deltaTime);
Then i tried mathf.clamp**[see line 60 above]**, i am using this line of code but what is happening is my soldier is standing at x=2.99, first it goes to 1.99, then on next click to 5.99 and good news is these positions are always same. Why he goes to 1.99, i want him to be at 2.99 only and its movement is instant, cant it be diognal,as my controller.Move… so that it look more realistic ??
if(LeftOrRight == true){
//Debug.Log("going left.."+LeftOrRight);
//controller.Move(directionSelector*transform.right * SwitchingSpeed * Time.deltaTime);
Vector3 pos = transform.position;
pos.x = Mathf.Clamp(pos.x,2.0f,2.0f);
transform.position = pos;
}
if(LeftOrRight == false){
//Debug.Log("entered");
//controller.Move(directionSelector*transform.right * (-SwitchingSpeed) * Time.deltaTime);
Vector3 pos = transform.position;
pos.x = Mathf.Clamp(pos.x,-2.0f,-2.0f);
transform.position = pos;
}