Fixing instantiated object in one direction?

Hey guys! How are you?

I'm developing a 2D shooter, side view. My character only walk in X axis and have a variable to verify the direction of the character. Depending on the direction, the bullets are instantiated from objects positioned on the sides of the main character. The problem is: everytime I shot in a certain direction and change the side of the character, the bullets are going in one direction also change direction.

For example: if I shot to right, the bullets go to right, but if I change the direction of character to left before gameObject's destruction, the bullets also go to left.

The bullet's code:

 var bulletSpeed     : float = 10.0;
 var distance        : float = 5000;
 var lifeTime        : float = 0.5;
 
 private var charging    : boolean = false;
 private var spawnTime   : float = 0.0;
 private var tr          : Transform;
 
 function Start()
 {
     tr = transform;
     spawnTime = Time.time;
 }
 
 function Update() 
 {   
 if(GameObject.Find("mainCharacter").GetComponent(scriptPlayerControl).moveDirection == 1)
     {
         tr.position += - tr.right * bulletSpeed * Time.deltaTime;
         distance -= bulletSpeed * Time.deltaTime;
 
         if(Time.time > spawnTime + lifeTime || distance < 0)
         {
             Destroy(gameObject);
         }
     }
     if(GameObject.Find("mainCharacter").GetComponent(scriptPlayerControl).moveDirection == 0)
     {
         tr.position += tr.right * bulletSpeed * Time.deltaTime;
         distance -= bulletSpeed * Time.deltaTime;
 
         if(Time.time > spawnTime + lifeTime || distance < 0)
         {
             Destroy(gameObject);
         }
     }   
 }

I want to fix the direction of the bullet in its firts direction till the destruction

Some help? Thanks!