My jump script isn't working?

My jump script isn’t working if anybody could tell me why and how to fix it that would be great

//The Script
var jumpVelocity : float = 800;
@HideInInspector
var grounded : boolean = false;
var maxSlope : float = 60;

function Update ()
{
    if (Input.GetButtonDown("space") && grounded)
        rigidbody.AddForce(0, jumpVelocity, 0);
}

function onCollisionState (collision : Collision)
    {
        for (var contact : ContactPoint in collision.contacts)
        {
            if(Vector3.Angle(contact.normal, Vector3.up) < maxSlope)
            grounded = true;
        }
}

function onCollisionExit ()
{
    grounded = false;
}

‘OnCollisionState’ should be ‘OnCollisionStay’