Error when building to HTML5 WebGL

whenever i try to build my game to webGL, i get this error:

Assets/Playerrespawn.js(5,5): BCE0005: Unknown identifier: 'clone'.

and i use the clone part in 5 other scripts and i get errors from them all. the scripts worked fine in the editor but it gets an error when i build it. can you please help?
here is one of the codes:

var Explosion : Rigidbody;
function OnCollisionEnter (col : Collision)
{
    if(col.gameObject.name == "Plane 1"){
    clone = Instantiate(Explosion, transform.position, transform.rotation);
    	clone.velocity = transform.TransformDirection( Vector3 (0, 0, 0));
    transform.position = Vector3(274.7, 10, 444);
    }
    if(col.gameObject.name == "Virus"){
    clone = Instantiate(Explosion, transform.position, transform.rotation);
    	clone.velocity = transform.TransformDirection( Vector3 (0, 0, 0));
    transform.position = Vector3(274.7, 10, 444);
    }
    if(col.gameObject.name == "InfectedRobot"){
    clone = Instantiate(Explosion, transform.position, transform.rotation);
    	clone.velocity = transform.TransformDirection( Vector3 (0, 0, 0));
    transform.position = Vector3(274.7, 10, 444);
    }
}

ps. the game is about a robot that destroys a virus.

Here is the code without errors :

#pragma strict

var explosion : GameObject;
var clone : GameObject;

function OnCollisionEnter (col : Collision)
{
    if(col.gameObject.name == "Plane 1"){
        clone = Instantiate(explosion, transform.position, transform.rotation);
        clone.transform.TransformDirection( Vector3 (0, 0, 0));
        transform.position = Vector3(274.7, 10, 444);
    }
    
    if(col.gameObject.name == "Virus"){
        clone = Instantiate(explosion, transform.position, transform.rotation);
        clone.transform.TransformDirection( Vector3 (0, 0, 0));
        transform.position = Vector3(274.7, 10, 444);
    }
    
    if(col.gameObject.name == "InfectedRobot"){
        clone = Instantiate(explosion, transform.position, transform.rotation);
        clone.transform.TransformDirection( Vector3 (0, 0, 0));
        transform.position = Vector3(274.7, 10, 444);
    }
}

But i did not understand what you wanted to do