Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.?

select  zee.TransId,zee.amount from OJDT t1
inner join
(

                SELECT
                    ojdt.TransId,
                    SUM(JDT1.Debit * 1 /100) as amount --
                FROM OJDT
                    INNER JOIN JDT1 ON JDT1.TransId = OJDT.TransId
                    INNER JOIN OACT ON OACT.AcctCode = JDT1.Account
                    INNER JOIN
                            (
                                SELECT
                                    AcctCode, AcctName, Head1Code, Head4Code, AcctTypeCode, Head1,
                                    CASE
                                        WHEN Head1Code='5140001' THEN 124
                                        WHEN Head1Code='5140002' THEN 188
                                        WHEN Head1Code='5140003' THEN 195
                                        WHEN Head1Code='511001'  THEN 104
                                        WHEN Head1Code='513002'  THEN 124
                                        WHEN Head1Code='513001'  THEN 104
                                        WHEN Head1Code='512021'  THEN 199
                                        WHEN Head1Code='511003'  THEN 108
                                        WHEN Head1Code='512012'  THEN 109
                                        WHEN Head1Code='512013'  THEN 110
                                        WHEN Head1Code='512014'  THEN 115
                                        WHEN Head1Code='512015'  THEN 112
                                        WHEN Head1Code='511002'  THEN 106
                                        ELSE ''
                                    END ItmsGrpCod
                                FROM
                                    DAccount
                            ) D1 ON D1.AcctCode = JDT1.ShortName
                    INNER JOIN OITB ON OITB.ItmsGrpCod = D1.ItmsGrpCod
                WHERE
                    OJDT.TaxDate BETWEEN '2013-12-01' AND '2013-12-31'
                    AND JDT1.Account NOT IN ('_SYS00000001371','_SYS00000006981','_SYS00000006876')
                    AND OJDT.TransCode IN ('JV')
                    AND OJDT.ObjType = '30'
                group by
                    OJDT.TransId
    ) zee on zee.TransId = t1.TransId
    where
        T1.TaxDate BETWEEN '2014-01-01' AND '2014-01-31'

Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.