RPG Levelling Script using GUI Text help

I am trying to modify an old script I have meant for showing and modifying a score that the player gets from destroying gameobjects into a levelling up script. So far the script works find for showing the current experience and even works with levlling up, but only up to level 2. Once level 2 is reached then the level up script ceases to work in that it stops changing the experience needed to level up and level when the current exp is greater than or equal to the experience needed. Here is the code that I have so far (sorry for the remnants of the old script cluttering it up):

 var hitTag = "bullet";
 var hitName = "bullet";
 var points = 10;
 
 static var current_xp = 0;
 var EXP_TO_LEVEL = 100;
 var user_level = 1;
 var exp_text : GUIText;
 var level_text : GUIText;
 var modify_exp = 1.5f;
 var xp_given = 10;
 
 function Update () {
 }
 
 function 
 ScorePoints()
 {
     gameObject.FindWithTag("Player").SendMessage("ScorePoints", points);
 }
 
 function addxp()
 {
         gameObject.FindWithTag("Player");
         current_xp += xp_given;
         if(current_xp >= EXP_TO_LEVEL)
         {
             user_level++;
             EXP_TO_LEVEL = Mathf.FloorToInt(EXP_TO_LEVEL * user_level * modify_exp);
                 
         }
 }
 
 function updatetexts()
 {
         exp_text.text = (current_xp.ToString() + "/" + EXP_TO_LEVEL.ToString());
         level_text.text = ("Level: " + user_level.ToString());
 }
 
 
 function
 OnTriggerEnter(col : Collider)
 {
 
 
     if ((col.gameObject.tag == hitTag) || (col.gameObject.name == hitName))
     {
         Destroy(col.gameObject);
         Destroy(gameObject);
         Debug.Log("Trigger " + col.gameObject.tag);
         addxp();
         updatetexts();
     }
 
 
 }
 
 function
 OnCollisionEnter(col : Collision)
 {
     Debug.Log("BBBB Collision " + col.gameObject.tag);
     if ((col.gameObject.tag == hitTag) || (col.gameObject.name == hitName))
     {
         Destroy(col.gameObject);
         Destroy(gameObject);
         Debug.Log("AAAAA Collision " + col.gameObject.tag);
         current_xp++;
         user_level++;
         addxp();
         updatetexts();
         EXP_TO_LEVEL++;
     }
 }