2.5D ledge hang with javascript

Hi there people.

I am trying to construct a script which will allow my character to jump up to a cube, cling to the edge and then allowed to jump up.

I am unsure how I would go about this for 2.5.d

how would I raycast from the top of the cube and the player detect it ?

heres what ive got so far - which is not working for me

 var ledge : Vector3;
 
 var Edge = transform.TransformDirection(Vector3(1,0,0));
 
 var hit : RaycastHit;
 
 
 function Update(){
 
 Debug.DrawRay(transform.position, -Edge*1, Color.blue);
 
 
 
 if(Physics.Raycast(transform.position, -Edge, hit,2)){
 
       hit.gameObject.SendMessage(transform.position.x, ledge);
 
 
 }
 
 }

I would appreciate some advice on this as everything Ive found so far is all about 3d platformers which I cannot make sense of.(fairly new to unity coding still)

Cheers