To edit the current entry select the Modify button or choose Edit/Modify Entry. After editing the entry select the OK button to apply your changes. If a format error is detected when you select OK a message will be displayed and you can correct the error. Type Esc or select the Cancel button to cancel editing an entry - any changes you made will not be saved.
For more information about editing fields in log entries see Log Entry Fields and Editing Fields.
As an alternative to the Modify button you can set an XMLog option that allows you to enter edit mode by clicking on any log field. Choose Options/Log Fields, Fonts, Default File... and turn Show Modify Button off.