Adding XP for each kill

i whant to know how can i add exp for each time i kill a monster

here is my script:

 var guiTextEXP : GUIText;
    var accumulatedExperiencePoints : int = 0;
    var levelExpRequirements : int = 1000;
    var currentLevel : int = 1;

    function Update () {
      if(accumulatedExperiencePoints >= levelExpRequirements) {
      levelExpRequirements += 1000;
      currentLevel += 1; 
      }
      guiTextEXP.text = accumulatedExperiencePoints+"/" + levelExpRequirements + "|" + currentLevel;
    }

You should probably add such code to the monster class since it should surely know when it's dying.

public abstract class Monster
{
    public int experienceValue { set; get; }
    public guiTextEXP xp;

    public void Die() {
        xp.accumulatedExperiencePoints += experienceValue;    
   }
}

public class Golem : Monster
{
    public void Start() {        
        experienceValue = 100;
    }
}

public class Spider : Monster
{    
    public void Start() {
        experienceValue = 50;
    }
}