AJAX :: Use Seadragon Control In Order To Show A Map?

i want to use seadragon control in order to show a map.

my code is

[Code]....

i am getting the following error:

Error on execution of Microsoft JScript: the 'undefined' is null or not an object

here:

AjaxControlToolkit.Seadragon.ImageLoader.prototype = {
_onComplete:
callback(image);
}
Seadragon.Debug.error(e.name +
}
}
},
function(callback, src, image) {this._downloading--;if
(typeof (callback) ==
"function") {try {catch
(e) {" while executing " + src +" callback: " + e.message,
e);