EnemyAi script

 var distance:float;
     var target : Transform;    
     var lookAtDistance : float = 15.0;
     var attackRange = 10.0;
     var moveSpeed = 5.0;
     var damping = 6.0;
     private var isItAttacking = false;
  
     function Update () 
     {
     distance = Vector3.Distance(target.position, transform.position);
  
     if(distance < lookAtDistance)
     {
     isItAttacking = false;
     renderer.material.color = Color.yellow;
     lookAt ();
     }   
     if(distance > lookAtDistance)
     {
     renderer.material.color = Color.green; 
     }
     if(distance < attackRange)
     {
     attack ();
     }
     if(isItAttacking)
     {
     renderer.material.color = Color.red;
     }
 }
  
  
 function lookAt ()
 {
 var rotation = Quaternion.LookRotation(target.position - transform.position);
 transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * damping);
 }
  
 function attack ()
 {
     isItAttacking = true;
     renderer.material.color = Color.red;
  
     transform.Translate(Vector3.forward * moveSpeed *Time.deltaTime);
 }

i wrote these codes and i take this error

Assets/Standard Assets/Scripts/Utility Scripts/MeshCombineUtility.cs(177,30): warning CS0618: UnityEngine.Mesh.SetTriangleStrip(int[], int)' is obsolete: Use SetTriangles instead. Internally this function will convert the triangle strip to a list of triangles anyway.' i'm new please help.