bouquet scan

i want to do a search for new channels but i dont want to erase my current services file or channels i just want to add any new channels that are found to my existing channels.does anyone know what option you select in the services scan bouqeut menu to do this.im preety sure the last time i selected update it erased my channels.thanks

 

anyone?

 

Leave current bouquets or keep current bouquets depending at the image.
Dead channels survive also.

 

cheers mate