raycast error

The script is attached to a cube that transform.translate. It is a simpler version of my script, Error(line 7): No appropriate version of 'UnityEngine.Physics.Raycast' for the argument list '(UnityEngine.Vector3, UnityEngine.Vector3, System.Type, float)' was found

 var canMove : boolean = false;
 var range : float = 100.0;
 function Update () 
 {
 var hit = RaycastHit;
 
 if (Physics.Raycast(transform.position, Vector3.forward, hit, range))
 {
         canMove = false;
 }
 }