Incorrect syntax near the keyword 'if'

Question

Error:-

 Incorrect syntax near the keyword 'if'

Sql Code:-

Alter Proc [dbo].[PRC_ACC_ACCOUNT_TRANS_INSERT]   

@Report varchar(50)   

as   
   
BEGIN   
-- Clear all the records from Account Trans   
   
TRUNCATE TABLE tbl_Acc_AccountTrans   
   
insert into tbl_Acc_AccountTrans   
(   
iAcID,iAcGrpid,iSlNo,iVoucherNo,vSeries,dtVoucherDate   
,nvVoucherType,nvFormType,dcDRAmount,dcCRAmount,nvNarration   
,iFinId,iBranchId,iCoId   
)   
   
-----------0 Get Opening Balance------------------------------------------   
   
--select * from tbl_Acc_AccountChild   
   
--select Feilds from Transaction tables   

if @Report='CASH'
--begin
select 
(select iAcID from tbl_Acc_AccountMaster Where vCategory='CASH BOOK')iAcID, 
(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tblSales.iAcID)iAcGroup, 
iSalesID,SerialNo as Voucher, 
(select Series from dbo.tbl_VoucherConfig where Series=tblSales.Series)as vSeries, 
dtDate,Series,'Sales'as FormType, 
Total as deDRAmount,0 as deCRAmount,'Narration' as vNarration   
,iFinId,iBranchId,iCoId  
 
from tblSales
--end 

Union All
select    
iAcID   
,(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tbl_Acc_AccountChild.iAcID)iAcGroup   
,1,1 as Voucher   
,'OP'as vSeries   
,getdate(),'OP' VoucherType,'A/c Master'as FormType   
,deOPDRBal,deOPCRBal,'Opening balance'   
,iFinId,iBranchId,iCoId   
   
from tbl_Acc_AccountChild   
 
union all 
------------tbl_Sales------------------------------------------------- 
select 
iAcID, 
(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tblSales.iAcID)iAcGroup, 
iSalesID,SerialNo as Voucher, 
(select Series from dbo.tbl_VoucherConfig where Series=tblSales.Series)as vSeries, 
dtDate,Series,'Sales'as FormType, 
Total as deDRAmount,0 as deCRAmount,'Narration' as vNarration   
,iFinId,iBranchId,iCoId  
 
from tblSales 
   
--union all
--if @Report='CASH'
--begin
--select 
--(select iAcID from tbl_Acc_AccountMaster Where vCategory='CASH BOOK')iAcID, 
--(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tblSales.iAcID)iAcGroup, 
--iSalesID,SerialNo as Voucher, 
--(select Series from dbo.tbl_VoucherConfig where Series=tblSales.Series)as vSeries, 
--dtDate,Series,'Sales'as FormType, 
--Total as deDRAmount,0 as deCRAmount,'Narration' as vNarration   
--,iFinId,iBranchId,iCoId  
-- 
--from tblSales
--end  

union all

-----------1 tbl_Acc_Voucher------------------------------------------   
select    
 iAcID   
,(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tbl_Acc_Voucher.iAcID)iAcGroup   
,RPID,iRPNO as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tbl_Acc_Voucher.iSeriesID)as vSeries   
,dRPDate,cVType VoucherType,'AcVoucher'as FormType   
,deDRAmount,deCRAmount,vNarration   
,iFinId,iBranchId,iCoId   
   
from tbl_Acc_Voucher   
   
union all    
-----------2 tbl_Acc_DrCrNote------------------------------------------   
select    
   
 iAcID   
,(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tbl_Acc_DrCrNote.iAcID)   
,NID,iNoteNo as Voucher,vSeries,dNoteDate,cVType VoucherType   
,'AcDrCrNote'as FormType,deDRAmount,deCRAmount,vNarration   
,iFinId,iBranchId,iCoId   
   
from tbl_Acc_DrCrNote   
   
union all    
-----------3 tbl_Acc_Contra------------------------------------------   
select    
   
 iAcID   
,(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tbl_Acc_Contra.iAcID)   
,CID,iCNo as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tbl_Acc_Contra.iSeriesID)as vSeries   
,dCNdate,'CO' VoucherType,'AcVoucher'as FormType   
,deDRAmount,deCRAmount,vNarration,iFinId,iBranchId,iCoId   
   
from tbl_Acc_Contra   
   
union all    
-----------4 tbl_Acc_Journal------------------------------------------   
select    
   
 iAcID   
,(select iAcGroup from tbl_Acc_AccountMaster where iAcID=tbl_Acc_Journal.iAcID)   
,JID,vJNO as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tbl_Acc_Journal.iSeriesID)as vSeries   
,djdate,'JE' VoucherType,'AcJournal'as FormType   
,deDRAmount,deCRAmount,vNarration,iFinId,iBranchId,iCoId   
   
from tbl_Acc_Journal   
   
union all    
-----------5 tblChitReceipts------------------------------------------   
select    
iAcId   
,isnull((select iAcGroup from tbl_Acc_AccountMaster where iAcID=tblChitReceipts.iAcID),0)   
,iRid,vSlipNo as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tblChitReceipts.iSeriesID)as vSeries   
,convert(datetime,convert(varchar,dTrDt,101)) as dTrDt    
,'CR'VoucherType,'ChitReceipts'as FormType   
,0 as deDRAmount,deCRAmount as deCRAmount,'Cash Receipt' as Narration   
,iFinId,iBranchId,iCoId   
from tblChitReceipts   
union all   
select    
nAccCashBankCode as iAcId    
,isnull((select iAcGroup from tbl_Acc_AccountMaster where iAcID=tblChitReceipts.nAccCashBankCode),0)   
,iRid,vSlipNo as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tblChitReceipts.iSeriesID)as vSeries   
,convert(datetime,convert(varchar,dTrDt,101)) as dTrDt    
,'CR'VoucherType,'ChitReceipts'as FormType   
, deCRAmount as deDRAmount,0 as deCRAmount,'Cash Receipt' as Narration   
,iFinId,iBranchId,iCoId   
from tblChitReceipts   
   
union all   
-----------6 tblChit Payment------------------------------------------   
select    
iAcId   
,(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tblChittyPayments.iAcID)   
,iPId,vVoucherNo as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tblChittyPayments.iSeriesID)as vSeries   
,convert(datetime,convert(varchar,dTrDt,101)) as dTrDt    
,'CP'VoucherType,'ChitPayments'as FormType   
,0 as deDRAmount,deCRAmount as deCRAmount,'Cash Payment' as Narration   
,iFinId,iBranchId,iCoId   
   
from tblChittyPayments   
   
union all   
select    
nAccCashBankCode as iAcId   
,(select isnull(iAcGroup,0) from tbl_Acc_AccountMaster where iAcID=tblChittyPayments.nAccCashBankCode)   
,iPId,vVoucherNo as Voucher   
,(select Series from dbo.tbl_VoucherConfig where SeriesID=tblChittyPayments.iSeriesID)as vSeries   
,convert(datetime,convert(varchar,dTrDt,101)) as dTrDt    
,'CP'VoucherType,'ChitPayments'as FormType   
,0 as deDRAmount,deCRAmount as deCRAmount,'Cash Payment' as Narration   
,iFinId,iBranchId,iCoId   
   
from tblChittyPayments   
   
   
update tbl_Acc_AccountTrans   
set iRootId=ISNULL((select iRootID from dbo.tbl_Acc_AccountGroup where iGroupID=tbl_Acc_AccountTrans.iAcGrpid),0)   
,iParentId=ISNULL((select iParentID from dbo.tbl_Acc_AccountGroup where iGroupID=tbl_Acc_AccountTrans.iAcGrpid),0)   
   
END