var EventManager =
{
    _registry: null,

    Initialise: function()
    {
        if (this._registry == null)
        {
            this._registry = [];

            // Register the cleanup handler on page unload.
            EventManager.Add(window, "unload", this.CleanUp);
        }
    },
    Add: function(obj, type, fn, useCapture)
    {
        this.Initialise();

        // If a string was passed in, it's an id.
        if (typeof obj == "string")
		{
            obj = document.getElementById(obj);
		}
        if (obj == null || fn == null)
		{
            return false;
		}

        // Mozilla/W3C listeners?
        if (obj.addEventListener)
        {
            obj.addEventListener(type, fn, useCapture);
            this._registry[this._registry.length]=({obj: obj, type: type, fn: fn, useCapture: useCapture});
            return true;
        }

        // IE-style listeners?
        if (obj.attachEvent && obj.attachEvent("on" + type, fn))
        {
            this._registry[this._registry.length]=({obj: obj, type: type, fn: fn, useCapture: false});
            return true;
        }

        return false;
    },

    /**
     * Cleans up all the registered event handlers.
     */
    CleanUp: function()
    {
        for (var i = 0; i < EventManager._registry.length; i++)
        {
            with (EventManager._registry[i])
            {
                // Mozilla/W3C listeners?
                if (obj.removeEventListener)
                    obj.removeEventListener(type, fn, "false");
                // IE-style listeners?
                else if (obj.detachEvent)
                    obj.detachEvent("on" + type, fn);
            }
        }

        // Kill off the registry itself to get rid of the last remaining
        // references.
        EventManager._registry = null;
    }
};