Error Message control not working for fileupload control validation

Hello,

I am trying to use Error Message control for fileupload control validation to display “Attachment is required” (at this time no file type validation required). But error message control not populating error msg if no file uploaded. The steps i followed:

  1. In Error Message control (message1), Show error message for selected “fileUpload1” .

  2. In fileUpload1 control, selected required field and required field error message as “Attachment is required”

  3. In fileUpload1 control, distableClientSideValidation is True.

I followed the above steps for other regular fields the validation works but why not for fileupload control. Help on this