Trigger problem

I working on multiplayer game.
I decided to add zombie.Created this simple code.

using UnityEngine;
using System.Collections;
using UnityEngine.Networking;

public class SimpleAI : NetworkBehaviour {
	public float walkSpeed = 5.0f;
	public float attackDistance = 2.0f;
	public float attackDemage = 10.0f;
	public float attackDelay = 1.0f;

	private float timer = 0;

	void OnTriggerStay(Collider other)
	{
		if (isServer) 
		{
			if (other.tag.Equals ("Player")) {
				Quaternion targetRotation = Quaternion.LookRotation (other.transform.position - transform.position);
				float oryginalX = transform.rotation.x;
				float oryginalZ = transform.rotation.z;

				Quaternion finalRotation = Quaternion.Slerp (transform.rotation, targetRotation, 5.0f * Time.deltaTime);
				finalRotation.x = oryginalX;
				finalRotation.z = oryginalZ;
				transform.rotation = finalRotation;
				//Uderzenie
				float distance = Vector3.Distance(transform.position, other.transform.position);
				if(distance > attackDistance) {
					transform.Translate(Vector3.forward * walkSpeed * Time.deltaTime);
				} else {
					if (timer <= 0) {
						other.SendMessage ("TakeDamage", attackDemage);
						timer = attackDelay;
					}
				}
				if(timer > 0) {
					timer -= Time.deltaTime;
				}
			}
		}
	}
}

But this code stoping working when 2 or more players are in the zombie trigger.
There is any way to get collider data for 2 or more object’s in trigger?

Issue solved by finding object by:

void OnTriggerEnter(Collider other)
	{
		if (other.tag.Equals ("Player")) 
		{
			player = other.gameObject;
		}
	}