Noob Raycast question

Hey, I was just wondering why there was nothing in the console when I click on a box with the tag, "Enemy".

 using UnityEngine;
 using System.Collections;
 
 public class fireScript : MonoBehaviour {
 
 
 
     // Use this for initialization
     void Start ()
     {
 
     }
     
     // Update is called once per frame
     void Update ()
     {
         Camera cam = Camera.main;
         if (Input.GetButton ("Fire1"))
         {
             RaycastHit hit;
             if (Physics.Raycast(cam.transform.position, cam.transform.forward, out hit))
             {
                 if (hit.collider.tag == "Enemy")
                 {
                     Debug.Log("OUCH!");
                 }
             }
         }
     }
 }