You buy it at the Veilstone department store.
Flash lost its HM status and became TM70 in Diamond, Pearl and Platinum.
you get the HM Flash after beating the electric gym leader, if i recall correctly
There is no HM Flash on Pokemon Diamond, I personally think its been replaced by HM05 Defog.
flash isn't a HM it is a TM
Look at "How do you get hm flash in blue?" On this site.
hm 05 you sped
The HM dive cannot be acquired in Pokemon diamond.
You get Hm flash from the hiker in granite cave in dewford.BEWARE!You can only use flash if you get the knuckle badge from Brawly
HM 05 is flash
you cant
flash
Hm05