Having Trouble Posting Highscores

Hello I am following this tutorial:

http://wiki.unity3d.com/index.php?title=Server_Side_Highscores

But whenever I try to post a highscore I get a 404 error, which I think it means that it can’t connect to the PHP file. I can connect to the PHP file through my browser though with the same URL though.

The c# code below with the addScoreURL is the PHP url i wan’t to connect to that’s giving me an error. What could be possible reasons for this?

using UnityEngine;
using System.Collections;
public class HSController : MonoBehaviour
{
    private string secretKey = "mySecretKey"; // Edit this value and make sure it's the same as the one stored on the server
    public string addScoreURL = "http://localhost/unity_test/addscore.php?"; //be sure to add a ? to your url
    public string highscoreURL = "http://localhost/unity_test/display.php";
    void Start()
    {
        StartCoroutine(GetScores());
    }
    // remember to use StartCoroutine when calling this function!
    IEnumerator PostScores(string name, int score)
    {
        //This connects to a server side php script that will add the name and score to a MySQL DB.
        // Supply it with a string representing the players name and the players score.
        string hash = MD5Test.Md5Sum(name + score + secretKey);
        string post_url = addScoreURL + "name=" + WWW.EscapeURL(name) + "&score=" + score + "&hash=" + hash;
        // Post the URL to the site and create a download object to get the result.
        WWW hs_post = new WWW(post_url);
        yield return hs_post; // Wait until the download is done
        if (hs_post.error != null)
        {
            print("There was an error posting the high score: " + hs_post.error);
        }
    }
    // Get the scores from the MySQL DB to display in a GUIText.
    // remember to use StartCoroutine when calling this function!
    IEnumerator GetScores()
    {
        gameObject.guiText.text = "Loading Scores";
        WWW hs_get = new WWW(highscoreURL);
        yield return hs_get;
        if (hs_get.error != null)
        {
            print("There was an error getting the high score: " + hs_get.error);
        }
        else
        {
            gameObject.guiText.text = hs_get.text; // this is a GUIText that will display the scores in game.
        }
    }
}

Changed my question.