How to create a pop-out join button

I would like to create a pop-out join screen like the one in the photo when you click the login button. Any tutorials on that please? The photo is a download below.  Thanks.

I don't think there are any. I have not seen one. I can't find reference to one in the forums either.

It has to be some where, the join button has this functionality.

Yes, there is a popup function. But you asked for a tutorial on how to do the same thing with the join form. Not a logon. Putting the join form on any page other than the join page itself is a pain it the neck let alone putting it in a popup. Oh, and BTW. The logon form has it's own prewritten popup function. The join form does not, so it would have to be coded by hand.

I answered your specific question which was for a tutorial on how to do it. And as far as i know there isn't one.