ahh - beer, got it! (I'm an old guy
)
One more question then, are each of your clients going to be accessing the same folder or a different one for each client?
.htaccess is a server-side (write) permission script for php/mysql so it was initially set up for php sign-in. That can be done but it's relatively complicated script and set-up.
Does your server have access protection for individual folders? What I mean is: can you password protect a certain folder (through your server admin panel) to not make it public and give only password access? If you do it would be very easy to simply give each client the url address of their particular page and assign a password through your server so that only they can view it. This would all be done on the server side, no scripts for you.
Would that be an option?