Required Field Validation in Uploadify jQuery Plugin

I am using jQuery Uploadify to upload multiple files.

I've followed this link :

http://www.aspsnippets.com/Articles/Implement-Uploadify-jQuery-Plugin-in-ASPNet.aspx

I am able to achieve everything according to my requirement. The trouble I'm now having is with validation.

I am having one textbox for UserName.

I am having one file upload control which is using Uploadify and it will upload user's images.

On button click I've to validate UserName and Uploaded Files.

I can check UserName using Required Field Validator but how can I check whether any file is uploaded on server or not?

If both fields (textbox, upload control) is validated then save the data into database.

let me know if more information is required from my end.

thanks in advance,

Dhruv