AjaxFileUpload: Send error to the user and stop processing of next upload

Hi,

I am using "AjaxFileUpload" control in my project. I am not clear how to abort the processing of AjaxFileUpload.

Let say, I had selected four files from "Select File" button and Click  on "Upload" button.

While each file is uploading on the server and if any file has validation failed on server side according to business logic at server side (not possible to put these validation in client side), AjaxFileUpload should abort the processing and should not process next files. I am using OnUploadedComplete event.

Also server side validation message should display in seprate label.

Can any one help me how to acheive it?

Thanks.