MicroBiz has the ability to suspend or put transactions on hold, as well as recall or reactivate these transactions.  

To suspend the current sale, just press the Hold button at the bottom right corner of the screen.  This saves the current transaction in a queue for recall at a later time.

There are several methods to reopen a hold transaction.  The easiest way is to use the Reopen Hold button on the Action Panel.

This opens a search windows displaying all transactions currently on hold.  There is a search box at the top to allow you to filter and find hold transactions by customer name, phone number and date.  To reopen a transaction, just click to highlight the line of the transaction to be reactivated, and press the Reopen Hold button at the bottom.  Simple as that.