Dear Experts.

I am trying these codes

declare @acc_code1 varchar(7)= '2310001'
declare @f_date1 datetime= '2016-11-01'

select acc_code,SUM(data1.dr)as dr, SUM(data1.cr)as cr,
sum(data1.dr)-sum(data1.cr)as balance,
(CASE 
 WHEN SUM(data1.dr)>SUM(data1.cr) THEN drcr='dr'
 WHEN SUM(data1.cr)>SUM(data1.dr) THEN drcr='cr'
 WHEN SUM(data1.cr)=SUM(data1.dr)THEN drcr=''
  END) 
 from
(
select code as acc_code, SUM(open_dr)as dr,SUM(open_cr)as cr
 from master where acc_code=@acc_code1 group by code
union all
select acc_code, SUM(dr_amount)as dr,SUM(cr_amount)as cr
 from vouchers where acc_code=@acc_code1 and date<@f_date1 group by acc_code
union all
select acc_code,SUM(dr_amount)as dr,SUM(cr_amount)as cr
 from cashsalp where acc_code=@acc_code1 and date<@f_date1 group by acc_code)
as data1
group by acc_code
order by acc_code

it says:

Msg 102, Level 15, State 1, Line 7
Incorrect syntax near '='.
Msg 156, Level 15, State 1, Line 21
Incorrect syntax near the keyword 'as'.
I am trying to get a new field called drcr.

Please help