Health bar stay in place

I have the following health system the problem is that if the screen resultion changes the green health bar leaves the gui it should show in. How do I make it so that the GUI texture for the health bar stays in place with different screen resolutions. using UnityEngine; using System.Collections;

 public class ShipHealth : MonoBehaviour {
 
     public int shipHealthMax = 100;// The ships Max health
     public int curShipHealth = 100; // The ships current health
     
     public GameObject shield; //The shield you are using
     public GameObject ship; // The ship itself
     public GameObject remains; // The remains
     public GameObject smoke; // The smoke
     
 
     public Transform player; // Ships transform
     public Transform location1; // The teleport after death location
     
     Rect box = new Rect(10, 50, 160, 17);// Starte Cordonates
     
     public Texture2D background; // Texture for the background of your health bar
     public Texture2D foreground; // Texture for the forground of your health bar
     public Texture2D Hud; // The hud of your health bar
     public Texture2D SpaceMan;  // The spaceman shown in the hud
 
     
 
     
 
     
     void Start()
     {
          StartCoroutine(addHealth()); // Starts the health recovery system
     }
 
 
     void Update () 
     {
         
             AddjustCurrentHealth(0); //keeps the current health uptodate
     
         if(curShipHealth == 0)//checks if the curship health is 0
         {
             StartCoroutine(dead());//Starts the death process.
             
         }
         
         if(curShipHealth <50)//Checks if maxHealth is set to less then 1.
         {
             smoke.SetActive (true);
         }
         else
         {
             smoke.SetActive (false); 
         }
     
 
     
     }
 
     public void AddjustCurrentHealth(int adj) //adjusts the current health
         {
         
             curShipHealth += adj;//This is to recieve heals or dammage to the CurHealth.  The number is passed in then assigned to curHealth.
         
         if(curShipHealth < 0)//Checks if the players health has gone below 0.
         {
             curShipHealth = 0;// If players health has gone below 0 set it to 0.
             
 
         }
         
         
 
         
         if(curShipHealth> shipHealthMax)//Checks if player health is higher then maxHealth.
             curShipHealth = shipHealthMax;//If players health is higher then maxHealth set it = to maxHeatlh
     
         if(shipHealthMax <1)//Checks if maxHealth is set to less then 1.
             shipHealthMax = 1;//If maxHealth is set below 1, this sets it to 1.    
         
     }
     
 
     void OnCollisionEnter(Collision collision) //When collided
     {
         if(!shield.activeSelf)// Checks to make sure the shield is not active
         {
             DamageInflictor di = collision.gameObject.GetComponent<DamageInflictor>();
            if(di) 
             {
                 print ("You Took Damage");
                curShipHealth -= di.damage;
             }
 
         }
         
     }
     
     void OnGUI()
         {
         
               GUI.DrawTexture(new Rect (0,Screen.height - 155,Screen.width,130),Hud); //Draws the Hud
             GUI.DrawTexture(new Rect (20,12,121,141),SpaceMan); // Draws the Spaceman
             
            // GUI.DrawTexture(new Rect(148, 38, box.width, box.height), background, ScaleMode.StretchToFill); //Draws the background health bar
            GUI.DrawTexture(new Rect(317, Screen.height -54, (Screen.width/7.5f)*curShipHealth/shipHealthMax, 7), foreground, ScaleMode.StretchToFill); // Shows the current health
             
             GUI.Label(new Rect(180,37,100,40),"Ship HP "+curShipHealth.ToString());//Displays the shields health in text.
             GUI.contentColor = Color.green;//Sets the text color red
 
 
 
    }
     
     IEnumerator addHealth ()//Add health to the ship shield
     {
         while (true)
               { 
            if (curShipHealth < 100)
         { // if health < 100...
               curShipHealth += 1; // increase health and wait the specified time
               yield return new WaitForSeconds(5);
            } 
         else
         { // if health >= 100, just yield 
               yield return null;
            }
         }
 
     }
     
     IEnumerator dead ()// The dead function
     {
         GameObject varGameObject = GameObject.Find("Star Blaster"); // Finds the main ship
         varGameObject.GetComponent<ShipThrusterControle>().enabled = false; // Finds the fly script and turns it off if we die
     
             ship.SetActive(false); // sets the ship invisible
             remains.SetActive (true);  ///Sets the reamins visible
     
         yield return new WaitForSeconds(3); //waits 3 seconds
     
             player.transform.position = location1.transform.position; //changes our position and gets us our of danger
             varGameObject.GetComponent<ShipThrusterControle>().enabled = true;// turns flight script back on
 
             curShipHealth = shipHealthMax; // Sets our health back to max
             ship.SetActive (true); //sets ship seable
             remains.SetActive(false); // turns remains off
     
     }
 
 }