SharePoint - How to provide a pop up error message when user does not have the rights to submit a form

Asked By kashish sinha on 09-May-13 06:05 AM

I have a users list and contain user a and user b, i have a form sendemail. when user A or B submits it sends email to the address which i have hardcoded in sharepoint designer

when user C submmits , mail should not go , it does not go , but i do not want user C to be able to submit, I want an error message to pop up when user C clicks the submit button .  I donot know how to go about this. do we have to do it in designer, Thanks in advance for any help

I do not know event handlers, so i prefer  a way to implement using sharepoint designer 
Kevin Davis replied to kashish sinha on 09-May-13 03:01 PM
Have you thought about not displaying the submit button based on permissions?