getting variables from other scripts C#

Hey i have been working on this script for a while and i have encountered a problem, and for the life of me i cant solve it. (using unity 5) when i run this script the TowerCanvas is always running instead of the MainCanvas and i have no idea why. i am using a raycaster to detect if the FoundHit variable is true or false. and it still works when the TowerCanvas is forcing itself on the screen. i have also made it so that when a press "Tab" MainCanvas pops up and TowerCanvas disappears, however when i click tab the Canvases switch for only one frame. i think there is something in the script forcing FoundHit to = true but at the same time i dont think so. there are only two scripts involved in the FoundHit var so there is no other script conflicting with it. if anyone knows how to help i will be so great full. here are the scripts:

using UnityEngine; using UnityEngine.UI; using System.Collections;

public class HUD : MonoBehaviour {

 bool FoundHit = false;

 public Slider TowerHealthSlider;
 public Slider BaseHealthSlider;

 int CurrantTowerHealth;
 int CurrantBaseHealth;

 public Canvas MainCanvas;
 public Canvas TowerCanvas;

 public int StartTowerHealth = 100;
 public int StartBaseHealth = 25;

 bool TowerDead;
 bool Basedead;

 public Text Ammo;
 public Text EnemiesLeft;
 public Text GunName;

 //may have to edit these later
 string CurrantAmmo = "12 / 24";
 string CurrantGunName = "Colt M1911";
 string CurrantEnemiesLeft = "Enemies Remaining = 10";
 

 public void Start () {

     CurrantBaseHealth = StartBaseHealth;
     CurrantTowerHealth = StartTowerHealth;
     Basedead = false;
     TowerDead = false;

     Ammo.text = CurrantAmmo;
     GunName.text = CurrantGunName;
     EnemiesLeft.text = CurrantEnemiesLeft;

     MainCanvas.enabled = true;
     TowerCanvas.enabled = false;
 }

 public void Update () {

     GameObject Camera = GameObject.FindGameObjectWithTag ("Camera");
     Clicking ClickingScript = Camera.GetComponent<Clicking>();
     bool FoundHit = ClickingScript.FoundHit;

     Ammo.text = CurrantAmmo;
     GunName.text = CurrantGunName;
     EnemiesLeft.text = CurrantEnemiesLeft;

     if (FoundHit = true){

         MainCanvas.enabled = false;
         TowerCanvas.enabled = true;
     }

     if (Input.GetKeyDown (KeyCode.Tab)) {

         MainCanvas.enabled = true;
         TowerCanvas.enabled = false;
         FoundHit = false;
     }
 }

 public void TowerTakeDamage (int TowerAmount) {

     CurrantTowerHealth -= TowerAmount;
     TowerHealthSlider.value = CurrantTowerHealth;
 }

 public void BaseTakeDamage (int BaseAmount) {

     CurrantBaseHealth -= BaseAmount;
     BaseHealthSlider.value = CurrantBaseHealth;
 }

}

and the other:

using UnityEngine; using System.Collections;

public class Clicking : MonoBehaviour {

 public float RaycastDistance = 50;

 public bool FoundHit = false;

 RaycastHit Hit;

 public GameObject Raycaster;

 string TagCheck = "TowerBase";
 

 void Update () {

     if (Input.GetKeyDown (KeyCode.E)) {

         FoundHit = Physics.Raycast (Raycaster.transform.position, transform.forward, out Hit, RaycastDistance);

         if (FoundHit && Hit.transform.tag != TagCheck){

             FoundHit = false;
             Debug.Log ("Not the TowerBase");
         }
         if (FoundHit && Hit.transform.tag == TagCheck) {

             Debug.Log ("You hit the TowerBase");
             //TowerCanvas.enabled = true;
         }
     }
 }

}

Thank you!