How to validate file upload using jquery Uploadify plugin

Hi sir,

hope doing well,

sir i used multiple file upload like gmail using j query in your website. it is superb.

but i want to validate file upload when it is empty and click on start upload it should show message please select a file. i tried a lot but it's not working but when i used some other file upload it' s working fine.

could u please help me.

it's urgent waiting for reply.

Thanks in advance.