You may edit, delete or reverse entries using this window

If the transaction information displayed in the Reconcile Accounts window is incorrect, you can choose to click the zoom to display the original transaction entry window.

If your records are changeable, you may edit the transaction. When you click OK, the updated information will appear in the Reconcile Accounts window. If you choose Delete Transaction from the Edit menu to delete the transaction, the transaction will no longer appear in the Reconcile Accounts window. Keep in mind, if you activated the Use Audit Trail Tracking preference, all deleted transactions are recorded. (Changes and entries recorded by Audit Trail Tracking)

If your records are unchangeable, you may reverse the transaction by choosing Reverse Transaction from the Edit menu. After a few moments, a new transaction, containing amounts exactly opposite to the original transaction, will be displayed. When you click Record, the reversal will be added to the Reconcile Accounts window. If you don't want the original entry and the reversal to appear the next time you reconcile, mark both entries to indicate they are cleared. (Choosing changeable or unchangeable transactions)