OnMouseDown Error?!

47654-capture.png

using UnityEngine;
using System.Collections;

public class CoinCollect : MonoBehaviour {

    public static int score = 100;

void OnMouseDown() {
	score += 20;

	Destroy(gameObject);
}

}

When i try to use this code with my game, this error comes up

You appear to have called your script filename OnMouseDown.cs. Don’t. Call it CoinCollect.cs instead.