anchor.diff:    :: Parse product name and id code from Product-Codes.txt
     :: http://ss64.com/nt/for_f.html
     echo.
  +  echo.           using "%_product_codes%" for Product ID list
  + 
     for /f "tokens=1,2 delims=^{" %%a in (%1) do (^
       if "%%b"=="" (echo ----- %%a -----) else (echo {%%b - %%a)
       call :uninstall {%%b
  
positive.code: 
  :no_codes_file
    echo.
    echo. "%1" not found
    echo.
    call :Usage
    goto :eof
  
  :Usage  
  
negative.code: ::
  set _product_codes=%1
  echo. ---------------------------------------------------------------------------
  echo.           Uninstall all ArcGIS products
  echo. ---------------------------------------------------------------------------
  if not exist "%1" goto :no_codes_file
  
  :: msiexec optional parameters here
  :: remove '/passive' to hide the pop-up progress window and run silently
  set _opt=/passive 
  if "%2"=="/silent" set _opt=
  
  call :from_file %_product_codes%
  
  