I'm using the PHP SDK on my site to let the users login using their FB acc.

After clicking on the login button there is a popup which asks for basic permissions. If the user click on Allow, my app can get the required data, it works all very well.

I'd like to make a callback for when the user click on the "Don't allow" button to show a message "For logging in to this website you have to provide us basic information. Please try again."

I know it's possible, i saw it once at another page, but after 2 hours of desperate search i decided to step back to SO :)

Thanks in advance!

DC