Persist FileUpload Control Value

Question

I have asp.net FileUpload control inside an update panel. When I click upload button, I am reading the file for some code, if code not found then I am showing ModalPopup for

Answer 1

This problem is somewhat well documented, the update panel is listed as not working with certain controls.

File upload, and tree view being 2 of the biggies.

To make it work you should use Triggers/PostbackTrigger