onmousedown issues

for some reason on the object print will run on the 0 click but never on the 1 or 2, why also the code never runs for anything other then 0???

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class PlanetName : MonoBehaviour {

public Text PlanetInfo;
public bool TextShowing;
public string planetName;

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

}

void OnMouseDown(){

		if (Input.GetMouseButtonDown (0)) {

		print("hit");

			//	Debug.Log ("true");
			PlanetInfo.gameObject.SetActive (true);

			PlanetInfo.text = planetName;

		}

		if (Input.GetMouseButtonDown (1)) {
                       print("hit");

			//	Debug.Log ("true");
		PlanetInfo.gameObject.SetActive (false);

			PlanetInfo.text = planetName;

		}

	}

}

Is your collapsed setting on inside of your console tab in the editor? that would make it look like only one message instead of the multiple.