Create Procedure with values save in parameter and again select

alter proc PRTODA(@SimpraPRNumber nvarchar(20),@SimpraDANumber int)
as
begin

declare @DRID int =0,@PRID int
declare @SOHID int =0,@CustomerID int =0
declare @Quantity int =0
declare @Rate decimal(15,2)=0.0
declare @CustomerIDOld int =0
declare @QuantityOld int =0
declare @RateOld decimal(15,2)=0.0
select @DRID=DRID,@PRID=PRID from prheader where simpraprnumber='CSDS1917492101'
select @SOHID=SOHID from drheader where drid=@DRID
select @CustomerID=CustomerID from soheader where sohid=@SOHID
select @Quantity=SOQuantity,@Rate=BasicRate from soheaderproductdetails where sohid=56115 
 --select @Rate as Rate,@Quantity as Quantity,@CustomerID as CustomerId
--Old
select @RateOld=BasicRate,@QuantityOld=Quantity,@SOHID=SOHID from dadetails where daid=485996 
 select @CustomerIDOld=CustomerID from soheader where sohid=@SOHID   
 --select @RateOld as RateOld,@QuantityOld as QuantityOld,@CustomerIDOld as CustomerIdOld
If(@Rate=@RateOld and @CustomerId=@CustomerIdOld and @Quantity=@QuantityOld)
begin
              insert into DADetailsLog select  *,GETDATE(),'@DeleteBy'  from dadetails where DAID=@SimpraDANumber
              update dadetails set PRID=@PRID where DAID=@SimpraDANumber
End
else
select 'invalid'

end