I don't know how dreamincode works, but how to post code is outlined where you post a new thread: immediately below the title box there is the text "Before proceeding, please make sure you are aware of the Community Guidelines and you have read the Hints before you make a post thread."

When posting to a forum you're new to, you should ALWAYS look for and read such things. It's not all legal mumbo jumbo, you get posting guidelines too. Code tags are number 7 of "Hints before you make a post", and it's called "hints ***BEFORE*** you make a post" for a good reason.