Euler angles changes when I don't do this.

I'm trying to rotate ball according to joystick, and when I test my script on Ipad simulator, at some unknown point game stops changing x and z which I need, and starts rotating y, which I dont need, and then vice-versa. Here is my code: using UnityEngine; using System.Collections;

 public class ControlPlayerGame : MonoBehaviour {
     // Use this for initialization
     public Joystick jsg;
     public Joystick jsg2;
     public float movespeed;
     public GameObject player;// ball that I move
     void Start () {
     movespeed=3.0f;
     
     }
     
     // Update is called once per frame
     void Update () {
         if((jsg.position.x!=0) || (jsg.position.y!=0))
         {
             this.gameObject.transform.position+=new Vector3(movespeed*Time.deltaTime*jsg.position.x,0.0f,movespeed*Time.deltaTime*jsg.position.y);
             Camera.mainCamera.transform.position+=new Vector3(movespeed*Time.deltaTime*jsg.position.x,0.0f,movespeed*Time.deltaTime*jsg.position.y);
             player.gameObject.transform.localEulerAngles+= new Vector3(jsg.position.y*50.0f*Time.deltaTime,0.0f,-jsg.position.x*50.0f*Time.deltaTime); // I think that problem is somewhere here
         }
         
         
     }
 }
 Why is this happening? Do you have any Ideas? That is the only script that I have in program, except joystick script from standard assets(mobile).