Batch Script: Delete Files from Folder not in another Folder

I found this on the web but it does the opposite of what it says. It deletes files that match. Can anyone help?

I use the following to compare files within different folders and delete the ones from first folder which does not exists on second one.

echo off
set "Folder1=C:\Documents and Settings\Administrator\My Documents\My Pictures"
set "Folder2=C:\Documents and Settings\Administrator\My Documents\My eBooks"

for /f "delims=" %%F in ('dir /b "%folder2%"') do (
if not exist "%folder1%\%%F" (
fc /b "%folder1%\%%F" "%folder2%\%%F"
if "%errorlevel%" EQU "1" (
  del "%folder1%\%%F" && echo Deleted "%%F"
) else (
  del "%folder1%\%%F" && echo Deleted "%%F"
pause
Exit