SQL Server 2008 :: Joining Two Columns To Same Table?

I have two tables: "Users" and "Messages".

The Messages table has a "UserFromID" and an "UserToID", indicating a message was sent from a user to a user.

The Users table has a UserID, FirstName, LastName and UserGroup.

Im trying to get all messages sent by or to a user in a specific group, with the First and Last names of the sending and receiving users.

Here is my tables and data:

CREATE TABLE tmp_users (userID INT, GroupID INT, UserName VARCHAR(10), FullName VARCHAR(100))
CREATE TABLE tmp_Messages (aKey INT IDENTITY, FromUserID INT, ToUserID INT, msg VARCHAR(100))
INSERT INTO tmp_users VALUES (1,1,'John','John Smith')
INSERT INTO tmp_users VALUES (2,1,'Jane','Jane Doh')
INSERT INTO tmp_users VALUES (3,1,'Bob','Bob Newheart')

[code]....

The query Im running so far is wrong, but here it is...

SELECT t.FromUserID, t.ToUserID, t.msg, u.UserName AS UserFrom,
u.GroupID AS FromGroup, u2.UserName AS UserTo, u2.GroupID AS ToGroup
FROM tmp_Messages t
LEFT JOIN (SELECT UserID, GroupID, UserName FROM tmp_users WHERE GroupID = 3) u

[Code] .....

im missing the details of one of the users.I know what the problem is, I just cant figure out how to get this working without using temp tables, which I cant do in the production version.