if you meant viridian you have to talk to the man in the radio station then go to the snorlax and use the pokegear. hold the stylus on the top of the radio thing and it will be a Flute. this will wake the snorlax so you can use diglett's cave to get to viridian.
hope that helped.
Aliza town
Blackthorne city is not in Pokemon Diamond but in Pokemon Heart Gold/Soul Silver
it should be in olivine city
blackthorn city
In fuchsia city.
by being awesome
dodo
The Pokemon Fan Club is in Vermillion City.
The Pokemon Daycare is on the route South of Goldenrod City.
ecruteak city
it is in the bottom right of olivin city
in pewter city