How can I use if statement after a CTE (SQL Server 2005)

Last night I was writing a simple T-SQL program something like this

DECLARE @ROLEID AS INT

SELECT @ROLEID = [ROLE ID] FROM TBLROLE

;WITH CTE
AS
( 
    SELECT * FROM SOMETABLE
)
IF (@ROLEID  = 1) 
BEGIN
      //SOMECODE
END
ELSE IF(@ROLEID  = 2) 
BEGIN
      //SOMECODE
END
ELSE
BEGIN 
      //SOMECODE
END

I found after compilation that it is throwing error something like "Incorrect statement near if"

What is wrong?

However, I did that by using some other way. But I wanted to know why it did not work!