Save Files
To save a document you have edited in DiffDog, use the Save 
or Save As 
buttons in the respective panes of the comparison window. Files can also be saved using the Close, Close All, and Save commands in the File menu.
In the File comparison tab of the DiffDog Options dialog box, you can also specify whether and how backup files should be saved.
To save a file:
Do one of the following:
•To save an individual file, click the Save button in its pane of the comparison window.
•To save an individual file under a new name or path, click the Save As button in its pane of the comparison window. The Windows Save As dialog box appears where you can specify the new name or path for the file.
•To save both files of a comparison, select the menu option File | Save. The Save files dialog box appears where you can select the files to be saved or choose to discharge the changes.
To save and close the files of a comparison:
1.Click the tab of the comparison window that contains the files you want to save and close.
2.Select the menu option File | Close.
3.If a file contains unsaved changes, the Save files dialog box appears. Make sure that the file's check box is selected and click Save selected. The file is saved and the comparison window is closed.
To save and close the files of all comparisons:
1.Select the menu option File | Close all.
2.For every comparison window that contains a file with unsaved changes, the Save files dialog box appears. Make sure that the file's check box is selected and click Save selected. The file is saved and the comparison window is closed.