A temporary network lock prevents other users on a network from editing the invoice on which you are currently working.

To understand this a bit more, it's helpful to look at network behavior.  Normally, when you are in the midst of making changes on an invoice, the program will lock out others.  But, if while you are working on the invoice, you make a menu choice or you select from a pop-up list (such as the vendors stock item pop-up), access is again restored to other users.

This system is fine on small networks or in situations where network users have their assignments and wouldn't normally work on the same Invoices.  On busy networks, however, you may wish to have assurance that no one else will attempt to make changes to the invoice at the same time you are working on it.  This feature enables you to have that assurance.

To turn it on, select FILE >> TEMPORARY NETWORK LOCK.  Or you can press SHIFT+F12.  When you turn it on, you'll see a "TL" (for "Temporary Lock") appear on the upper right hand corner of the Main Invoice Screen.

After turning it on, you'll be able to edit or otherwise make changes to the invoice.  But if another user on another computer goes to the same invoice, they will see a colorful Network "Lock" indicator in the upper right hand corner.  That means, of course, that they are temporarily locked out of that invoice.  They can move to and work on another invoice, but your invoice is blocked until you finish your work.

To remove a temporary network lock, simply move to another invoice.  As soon as you move to another invoice, the lock is removed and others can access it.