destroy object collision problem

I have a mouse script where to drag the object A...

var screenSpace;

var offset;

function OnMouseDown(){
    //translate the cubes position from the world to Screen Point
    screenSpace = Camera.main.WorldToScreenPoint(transform.position);

    //calculate any difference between the cubes world position and the mouses Screen position converted to a world point  
    offset = transform.position - Camera.main.ScreenToWorldPoint(Vector3(Input.mousePosition.x,Input.mousePosition.y, screenSpace.z));
}

/*
OnMouseDrag is called when the user has clicked on a GUIElement or Collider and is still holding down the mouse.
OnMouseDrag is called every frame while the mouse is down.
*/

function OnMouseDrag () {
    //keep track of the mouse position
    var curScreenSpace = Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z);

    //convert the screen mouse position to world point and adjust with offset
    var curPosition = Camera.main.ScreenToWorldPoint(curScreenSpace) + offset;

    //update the position of the object in the world
    transform.position = curPosition;
}

THen I apply the destroy script to object B..

function OnTriggerEnter(hit:Collider){
    if(hit.gameObject.tag=="cube"){
        Destroy(gameObject);
    }
}

Object A have collision Object B is mark isTrigger

when I drag the Object A to object B.. Object B does not destroy.. How can I fix it?Blockquote

OnTriggerEnter is not being fired. From the docs:

Note that trigger events are only sent if one of the colliders also has a rigid body attached.