I have problem with synchronize multiplayer player position...

Hi to all... I'm trying to do a simple Multiplayer game... I have a player prefab like this:

but with script:

 if (stream.isWriting)
         {
             syncPosition = rigidbody.position;
             stream.Serialize(ref syncPosition);
 
             syncPosition = rigidbody.velocity;
             stream.Serialize(ref syncVelocity);
         }
         else
         {
             stream.Serialize(ref syncPosition);
             stream.Serialize(ref syncVelocity);
 
             syncTime = 0f;
             syncDelay = Time.time - lastSynchronizationTime;
             lastSynchronizationTime = Time.time;
 
         syncEndPosition = syncPosition + syncVelocity * syncDelay;
         syncStartPosition = rigidbody.position;
     }
 }

or with script:

 if (stream.isWriting)
         {
             Vector3 pos = transform.position;
             Quaternion rot = transform.rotation;
 
             stream.Serialize(ref pos);
             stream.Serialize(ref rot);
         }
         else
         {
 
             Vector3 pos = Vector3.zero;
             Vector3 velocity = Vector3.zero;
             Quaternion rot = Quaternion.identity;
             Vector3 angularVelocity = Vector3.zero;
             stream.Serialize(ref pos);
             stream.Serialize(ref rot);
         }
     }

the player spawn but the position isn't synchronized... Yes i have a component rigidbody in the prefab "Personaggio" and all scripts are here like this:

then what i have to do? Please help i'm in panic!

Ps: the ifs are into the void:`void OnSerializeNetworkView(BitStream stream, NetworkMessageInfo info)` and i have forgot that before the ifs there are the code:

 Vector3 syncPosition = Vector3.zero;
 Vector3 syncVelocity = Vector3.zero;

Please help!