A trigger is activating scripts of other triggers

So I am trying to make a line of platforms that rise up as the player enters their triggers, supposedly each platform has it's own trigger.

for the first five everything works fine but the sixth and sventh rise up when the player steps into the first one( each trigger can only be linked to one platform )

I also tried putting a different script on them but to no avail

Picture:http://s927.photobucket.com/user/FRESHERMAW/media/2014-05-02_0024.png.html?filters[user]=109301372&filters[recent]=1&sort=1&o=0

here's the script I am using

 using UnityEngine;
 using System.Collections;
 
 public class Trigger_Test : MonoBehaviour {
     public GameObject stair1;
     bool risertrig=false;
     public float height=76f;
     public float speed=1000f;
     // Use this for initialization
     void Start () {
     
     }
 
     void OnTriggerEnter(Collider trigger){
         if (risertrig == false) {
             risertrig = true;
         }
     }
 
     // Update is called once per frame
     void Update () {
     //    Debug.Log(stair1.transform.position.y);
         if (risertrig == true) {
             print ("true");
                 }
 
         if (risertrig == true) {
             print ("false");
         }
 
 
         if(risertrig == true){
             stair1.rigidbody.velocity=transform.TransformDirection (Vector3.up * speed *Time.deltaTime);
 
         }
 
         if (risertrig == true) {
             if (stair1.transform.position.y >= height) {
                                 risertrig = false;
                 stair1.rigidbody.velocity=transform.TransformDirection (Vector3.zero );
                         }
                 }
 
     }
 
 
 
 
 }
 

[1]: http://s927.photobucket.com/user/FRESHERMAW/media/2014-05-02_0024.png.html?filters[user]=109301372&filters[recent]=1&sort=1&o=0hill\C+Valley\2014-05-02_0024.png