How to Make an animation play Once?

My current script: What can i do so than when my fps controller enters the collision box area for the second time, it doesnt replay the animation?? thx in advance!!

var Animator : GameObject; //Assign this in the editor character with animation

function OnTriggerEnter(){
    Animator.animation.Play("Animination"); // name the animation to be played
}``

using UnityEngine;
using System.Collections;

public class guiText : MonoBehaviour {

public GameObject gg;
public GameObject gg1;
public GameObject gg2;
public GameObject gg3;

public static int count;

public bool one,two,three,four;


// Use this for initialization

void Start () {
    
	gg.animation.Play("Des");
    one = true;
    two = true;
    three = true;
	four=true;
}

// Update is called once per frame
void Update () {

  if(Input.GetButtonDown("Fire1"))
	{ 
		//gg1.animation.Play("Ap"); 
		count++; 
	}
	if(count==1 && one)
	{ one = false;
		//gg1.animation["Ap"].wrapMode = WrapMode.Once; 
		gg1.animation.Play("Ap");
	} 
	if(count==2 && two)
	{
		two = false; 
		gg2.animation.Play("APP1");
    } 
	if(count==3 && three) 
	{ 
		three = false; 
		gg3.animation.Play("APPS2");
    }
	if(count==4 && four) 
	{ 
		four = false; 
		Application.LoadLevel("Question");
		
    }
    } 
    }

this is a simple code to play animation once if u click mouse. modify as u wish.
under that . i think it is working.

try this

function OnTriggerEnter(){
    Animator.animation.Play("Animination"); // name the animation to be played
    Animator.animation.PlayQueued ("PreviousAnimation",QueueMode.CompleteOthers);


}``