So, I have a script where it only works when I reapply it to the player before I run the game, and it doesn't work anymore when I load a different scene and go back to the main game where that script is.

Here is my script

pragma strict

private var showGUI = false; var skin : GUISkin; var points = 0; private var xpManager : XPManager;

function Start () { xpManager = GetComponent(XPManager); }

function Update () {

 if(showGUI == true)
 {
     Screen.showCursor = true;
     Time.timeScale = 0;
 }
 
 if(xpManager.curXp >= xpManager.totXp)
 {
     showGUI = true;
     points++;
 }

}

function OnGUI()

{ GUI.skin = skin;

 if(showGUI == true)
 {
     GUI.Box(new Rect(Screen.width / 2 - 200, Screen.height / 2 - 200,400,400), "Level Up");
     
     var player : PlayerManager = GameObject.Find("Player").GetComponent("PlayerManager");
     
     GUI.Label(new Rect(Screen.width / 2 -60, Screen.height / 2 -150,400,400), "Move Speed: " +player.speed);
     
     GUI.Label(new Rect(Screen.width / 2 -170, Screen.height / 2 +145,400,400), "Points: " +points);
     
     if(GUI.Button(new Rect(Screen.width / 2 - 150, Screen.height / 2 -155,40,40), "+"))
     {
         if(points >0)
         {
         player.speed++;
         points--;
         }
         else if(points <=0)
         {
             player.speed = player.speed;
         }
     }
     
     GUI.Label(new Rect(Screen.width / 2 -60, Screen.height / 2 -110,400,400), "Shoot Delay: " +player.shotDelay);
     
     if(GUI.Button(new Rect(Screen.width / 2 - 150, Screen.height / 2 -115,40,40), "+"))
     {
         if(points >0)
         {
         player.shotDelay-=.05;
         points--;
         }
         else if(points <=0)
         {
             player.shotDelay = player.shotDelay;
         }
     }
     
     if(GUI.Button(new Rect(Screen.width / 2 -100, Screen.height / 2 +90,200,50), "OK"))
     {
     Screen.showCursor = true;
     Time.timeScale = 1;
     showGUI = false;
     }
 }

}