deathmatch point system

for my splitscreen shooter I want the player to be able to score points if they kill another player, at the moment when the players die they drop yellow point cubes, how would I change my player health script to add one point to the killer’s killcount?

this is the healthscript I’m using, it’s in Javascript

var PointCube : Transform;
var spawneffect : Transform;
var SpawnPoint : Transform;
var respawn : boolean = false;
var health:float = 90;

function Damage(dmg:float){
health -= dmg;
}

function Update (){
if(health <=0){

Instantiate (PointCube,transform.position,transform.rotation);

transform.position = SpawnPoint.position;

Instantiate (spawneffect,transform.position,transform.rotation);

var audio: AudioSource = GetComponent.();
audio.Play();
audio.Play(44100);

health += 100;
}

}

void Damage(float Dmg)
{
health -= Dmg;
if(health<=0)
{
//instantiation stuff
//if you are sure about the killer who killed this player
// increase killer’s kill count here simply by taking an instance of the killer script and accessing the value of it
//or declare killer script here in your “myplayer.cs” and drag drop the gameobject on which killer script attached and use the reference variable to increase count(killerscript.killcount+=1)
////if you are NOT sure about the killer who killed this player
//pass the player id along with dmg value to this function and based on the player id , increase kill count to the respective player
// or pass the gameobject to this method along with dmg and getcomponent killerscirpt from the gameobject that you passed and access the killcount value
//or simple the killerscript to this method along with dmg access the killcount value
//Make sure your killerscript conists of the variable killcount with public as accessmodifier
}
}

Hope this may help you.
-Nsks