I'm wanting to have 'Prevent Duplicate Check-in' enabled, so children aren't reprinting their tags over and over (and changing the parent security code at the same time); however need to be able to have children check out and then back in again later.

I was thinking the easiest way would be to modify the check-in block to check the current check-in state and if they are actively checked in to not allow check-in.  This would mean that if I have 'Prevent Duplicate Check-in' turned off, then children who have checked out will be able to do a 'duplicate check-in', but otherwise not. 

The alternative, as I see it, would be to adjust the way the 'Prevent Duplicate Check-in' identifies a check-in to change it from checked-in to that service to currently have an active check-in.

Logically, the first seems to be the easiest, and should be quite simple, and I suspect that I would do this in PersonSelect.ascx.cs; perhaps under ' protected void rSelection_ItemCommand( object source, RepeaterCommandEventArgs e )', however I'm having trouble getting the code to work.

Is anyone able to help me here? 

Thanks in advance!

Current version 7.0
Locale en-au 

Dave.