You can use the Status Check feature in senior Circulate to check whether a resource is currently on loan or not.
This can be useful if you have Circulate open and you have the book to hand. With one scan you can be notified what status the book currently has.
When Circulate is opened, click 'Status Check' from the left menu and the Status Check box will open.
Using the barcode scanner, scan the resource barcode number (not the ISBN).
The message that shows in the 'Status' box will show whether the resource is currently marked as available, reserved, overdue, on loan or missing.