Browser -> Unity communication

Unity Engine
1

Unity → Browser works fine
Browser → Unity isn’t working.

In my .html file:

<script type="text/javascript">
    function CookiePrefs_init(name, callback) { 
        var unity=u.getUnity(); 
        if ( unity ) { 
            unity.SendMessage( name, callback, document.cookie); 
        } 
        else { 
            alert('Could not find Unity. Preferences will not be loaded'); 
        }
    }
</script>

In CookiePrefs.cs

#if UNITY_WEBPLAYER
    /// <summary>
    /// Loads the preferences from the cookie.
    /// </summary>
    public void LoadPreferences()
    {
        Application.ExternalCall("CookiePrefs_init", transform.name, "_ReadCookiesCallback");
    }

    /// <summary>
    /// Callback for javascript to send the cookie to
    /// </summary>
    /// <param name="cookie_string">The cookie</param>
    public void _ReadCookiesCallback(string cookie_string) 
    {
       if (cookieContents == null) 
            cookieContents = new Dictionary<string,string>();

        string[] split  = cookie_string.Split(';');
        foreach(string element in split ) 
        {
            string[] key_value = element.Split('='); 
            if(key_value.Length == 2 && !key_value[0].StartsWith("_utm"))
                cookieContents.Add(key_value[0].Trim(), key_value[1]); 
        }
        loaded=true;
    }
#endif // UNITY_WEBPLAYER

LoadPreferences is called from Start, the script is attached to an object named CookiePrefs which is at the root of my scene.
CookiePrefs_init gets called, u.getUnity() returns the correct result but SendMessage doesn’t do anything.

I can’t find anything useful, the only examples I find are for older versions of Unity so I’m starting to wonder if this isn’t just borked in the current version.

2

According to:
http://docs.unity3d.com/Manual/UnityWebPlayerandbrowsercommunication.html

you may be missing some code to grab the actual unity object to send the message to…

<script type="text/javascript" language="javascript">
<!--
//initializing the WebPlayer
var u = new UnityObject2();
u.initPlugin(jQuery("#unityPlayer")[0], "Example.unity3d");

function SaySomethingToUnity()
{
    u.getUnity().SendMessage("MyObject", "MyFunction", "Hello from a web page!");
}
-->
</script>