Variable changing from other script does not work.

Good time of day to everybody. Currently, I am making a little strategy game in which you can select and command units. I have written a little script for selecting units on the gamefield. However, as is with any script that I write on my own, it does not work. It should work but it has two problems: 1. It does not recognize the isSeleted bool 2. It throws in this error "Expression denotes a method group, where a variable, value or type was expected." Here is my code:

 void Update () {
     units = GameObject.FindGameObjectsWithTag ("Unit");
     if (Input.GetMouseButtonDown (0)) {
         RaycastHit2D hit = Physics2D.Raycast (transform.position, Input.mousePosition);
         if (hit != null && hit.collider != null) {
             hit.transform.GetComponent<ShipAI>.isSelected = true;
         }
     }

 }

Here is the script I am trying to access:

 void Update (){
     if (isSelected) {
         Debug.Log ("I am the chosen one!");
     }
 }