You have to reverse a journal entry when you originally enter it. If you want to reverse a journal entry after the fact you have to manually create a reversing entry with a new journal number and the credits/debits reversed.

If I'm understanding correctly, you want to reverse an entry that's already posted.  To do that, you need to create a new entry with all the details (date and accounts) of the original except that the amounts are reversed.

It sounds as if you're following the instructions for creating a Reversing Journal Entry - this is done when you want to record something in one time period, then automatically reverse it in another.  This is useful for accruing a transaction that has already been recorded in a future period, like a payment that is made annually in January but applies to the previous year.

Thanks to both of you! That's the part that was confusing me because the instructions in the help section don't mention that one little fact. It simply says how to reverse an entry but it doesn't explain that these instructions only apply when you first enter the entry; so when you do that it creates a double entry all at once. I sorted it all out by creating a new entry to reverse it. Thanks again!