The Save Frames dialog will be displayed, allowing you to enter the directory to save all the OGF files to. The OGF files will have the same names as the frames in the animation. This means that is frames have duplicate names, some will be overwritten. Use the Rename command on the Frame Menu to fix this.
Any OGF files that already exist in the directory with the same name as frames in the animation will be overwritten.
If the directory does not exist, an error dialog will be displayed.