Navmesh Tag

I made a game with an enemy which follows you by the tag but not all enemies follow the character.
If someone can improve the script i would be very thankfully.

usingUnityEngine;
usingSystem.Collections;

publicclassEnemy : MonoBehaviour {

publicTransformtarget;
NavMeshAgentagent;

//Usethisforinitialization
voidStart () {
agent = GetComponent<NavMeshAgent>();
}

//Updateiscalledonceperframe
voidUpdate () {
agent.SetDestination(GameObject.FindGameObjectWithTag("Player").transform.position);
}
}