H&M has an a web site, but does not allow for online shopping. It's mainly to find locations!
I don't think there is a "shop" hm but if you mean surf you get it from the end of the safari zone. Please specify for more info
go to the pokeshop in shop,center and more then u click on the tm/hm option u will find the tms
its not an HM anymore you have to find it.
you can find HM's in hole game
if you lose a HM by putting a Pokemon in the day-care, you can just teach it the HM again unless if you have tossed it. if it is a TM, you can by a few from the Lilycove department store or from the casino place in Mauville City, but otherwise you can't get them back.
You can find them in dungeons, in kelcon's shop in treasure town (the right one) , or get them as rewards for completing jobs
You find the HM Defog in the cave in solaceon town where you find the unknown
He lives in the first house to the right of the Lilycove Department Store. There's a sign out front, so not too hard to find.
flash isn't a HM but a TM and you can purchase it at goldenrod city super store thing
In Flora sky the HM 'cut' is actually called HM air cutter. You find this HM in the underground tunnels of Searound city.
You buy it at the Veilstone department store.
You can get Flash as TM70 from the Elder in the Sprout Tower. Additionally you can buy it with your in-game money in the Goldenrod Department Store.