well you need 200k to get to johto. you purchase a surfboard, then go west of viridian through the elite 4 building. after following the path and entering the cave, you will surf across to Johto.
Oh hm.. thank you <img src="http://www.pokemon-world-online.net/forum/public/style_emoticons/<#EMO_DIR#>/ChikoritaSmile.png" class="bbc_emoticon" alt="" />
I'll never get 200K lol how much does a Duskull and a Cubone worth? <img src="http://www.pokemon-world-online.net/forum/public/style_emoticons/<#EMO_DIR#>/TogepiCry.png" class="bbc_emoticon" alt=":cry:" />
As Merse said you cannot use the train the first time you go from one region to the next. There is a badge requirement for each train destination in the second region so you must still surf to get there first time.
In future before posting in someone else's post after a forum search please check the date on it, if it's an older post like this one just make a new one of your own to avoid any confusion.