script working but how can i generate object only Y axis? I don't know how to change function of this Script

using UnityEngine; using System.Collections;

public class CloudsGenerator : MonoBehaviour {

 public GameObject Clouds;
 public Transform generationPoint;
 public float distanceBetween;

 private float platformWidth;

 // Use this for initialization
 void Start () {
 
     platformWidth = Clouds.GetComponent<BoxCollider2D> ().size.x;
 }
 
 // Update is called once per frame
 void Update () {

     if(transform.position.x < generationPoint.position.x)
     {
         transform.position = new Vector3(transform.position.x + platformWidth + distanceBetween,transform.position.y,transform.position.z);
        Instantiate (Clouds, transform.position,transform.rotation);

 }
 }