How to get distance between two object by using a pinpoint? Or Tag?

I was able to get distance of two objects using raycast but I need to get distance using the raycast to pin point one object then to another game object and get the distance between those two.

Here is a screenshot:

Here is my code so far.

using UnityEngine; using System.Collections;

public class RaycastDistance : MonoBehaviour {

 public GUIText distanceText;//This will hold the value of distance from Point A
 public GUIText distanceBText;//This will hold the value of the distance from Point B
 public Transform other;

 private float distance;

 void Start ()
 {
     distance = 0;//Distance initial value set to 0
     SetDistanceText ();//Use to call the function SetDistanceText
     distanceBText.text = "";

 }

 // Update is called once per frame
 void Update ()
 {

     RaycastHit hit;
     Vector3 up = transform.TransformDirection (Vector3.forward);//This where the raycast should point either forward,up,down,etc.0
     Debug.DrawRay (transform.position, up * 100, Color.green);//Raycast draws line in green

     if (Physics.Raycast (transform.position, up, out hit)) 
     {
         distance = hit.distance;
         distanceText.text = "Distance: " + distance.ToString();
         distanceBText.text = "YOU GOT THE DISTANCE MEASUREMENT!!";
         Debug.Log("This distance is " + hit.distance);
     }
 
 }

 void SetDistanceText()
 {
     distanceText.text = "Distance: " + distance.ToString();
 }

}

Please really need help. Thanks.