Profile Photo - how do I make mandatory?

I have D7, was wondering how to make it mandatory for a new member to upload a photo or at least choose an avatar?  Thanks

See here : http://www.boonex.com/unity/extensions/entry/Mandatory_Photo_on_Join

Please not this just make the field mandatory on the join form. If the choose to by-pass the Set Avatar page, then it will not get uploaded. Read my comments to other members for suggestions.

thanks for replying, i will try in a while