Broadcast message not working

using System.Collections;
using UnityEngine;

public class SelectScript : MonoBehaviour {
	public bool Selected;
	public Camera cam;
	void Awake() {
		cam = Camera.main;
	}
	// Update is called once per frame
	void Update () {
		
	}
	// when clicked on with left mouse broadcast unselect and set selected to
	void OnMouseDown() {
		if (Input.GetMouseButton (0)) {
			// false
			if (gameObject.tag == "Floor") {
				SendMessage ("UnSelect");
				Selected = false;
				// true
			} 
			else if (gameObject.tag == "T-A") {
				Selected = true;
			}
		}
	}

	// UnSelect the unit
	public void UnSelect()
	{
		Selected = false;
		Debug.Log ("UnSelect");
	}
}

Any help us apperciated

Please check if the script’s gameObject is active. This function does not work if it is inactive.

Yeah it is and thanks for the suggestion