SharePoint 2010 - Message: Access is denied.WebResource.axd

I have been creating Sharepoint application page, which is deployed in Sharepoint 2010 14\TEMPLATE\LAYOUTS directory. In browser my page is working fine. But on the page i am using asp:FileUpload control for uploading images.

there is a javascript function, which i change image src/path when asp:FileUpload onChange event is called. this is working also fine.

Now the problem is, after changing image src/path through javascript onChange event. Page postback is causing an error like,

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Tr开发者_如何学编程ident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; InfoPath.2) Timestamp: Thu, 13 Oct 2011 13:08:03 UTC

Message: Access is denied.

Line: 350 Char: 9 Code: 0 URI: http://saif-pc:81/WebResource.axd?d=0a7ZWROgcpePPy6XDUEhLl9SVCuQxHFrPdtua4kZN2U8VKZ9a4kNK11sx9E5Ae_oIgpqGL4O9QaXCripQx59D309Yoc1&t=634208957469717278

I have spent much time on googling, but not find any solutions.

Please any one help me.

Thanks in advance.