it wont let me add a message to the trades

[Tae yamash]

same as title

[Amaranthos]

Hey there;
CS has a user group for people who have never made any posts on our forums before. As long as someone is in this "newly registered" usergroup, they will be unable to send trade messages and private messages.
This is a measure to protect the site against spammers and other inappropriate content - as every user's first post needs to go through mod approval first it helps us cut down on spam accounts.

You were likely trying to send those trades when you still had no approved forum posts. Now that you do, though, you should be able to send trade messages c: