Why isn't this script working? (OnMouseDown)

I tried but it does nothing at all.

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

public class MosueCLick : MonoBehaviour {

    function OnMouseDown()
    {
        print("The state of florida has asked us too");
    }
}

Please also post, if you answer the question, how the right way would be.

You have a C# script here but you try to define a UnityScript function in it. A C# function / method looks like this:

void OnMouseDown()
{

}

Also note that you have a typo in your classname. Keep in mind that the script and classname have to be the same.