Enemy reorienting for player

Hi guys, in this code my gameobcjet is reorienting to player positin. I am trying to use the script on 2D game, and i need the object reorienting only the X axis.

Because with Y reoriententaion it will be like a flutuable gameobject.

Can anyone help me here??

Thanks!

 var player: GameObject;
     var rotVel : float ;
     var transVel : float;
     
     
     function Update () {
     
     
     
         rotVel = 1;
         transVel = 2;
     
         Aproximar ();
     }
     
     
     function Aproximar ()
     {
         
         
     
         var dir : Vector3 = player.transform.position - transform.position;        
         
         // Reorient NPC towards it
         transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.LookRotation(dir), Time.deltaTime * rotVel);
         transform.eulerAngles = new Vector3(0, 0, 0);
             
         
         
         if (dir.magnitude <= 2)
         {
             rigidbody.velocity = Vector3.zero;
             
         }
         else
         {
             rigidbody.velocity = dir.normalized * transVel;    
         }
     
         
     }