Unable to check if grounded

Hello, I am just starting out in Unity and UnityScript and am trying to check if my 2D platform sprite is grounded. I am having trouble implementing the code from the 2d tutorial demo and have looked at a number of answers on here but must be doing something wrong as it's still not working. Here is my code:

 private var groundCheck : Transform;
 private var isGrounded : boolean;
 
 function Start () {
 
 groundCheck = transform.Find("groundCheck");
 
 }
 
 function Update () {
 
     isGrounded= Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));  
     Debug.Log(isGrounded);
 }

It doesn't matter where my player is, isGrounded always returns False.

All help greatly appreciated