How To Return Value From Dynamic Query Or Set The Value

Hii I am Varun  i have a problem with the dynamic stored procedure

This is my stored procedureALTER PROCEDURE dbo.sp_TimeTableAdjustment1

(@TeacherID_OnLeave numeric(9),

@DateFrom datetime ,@DateTo datetime , @UserID numeric(9)

)

AS

declare @flag as numeric(9)

declare @year as varchar(4)

set @year=(select batch from batchmaster where iscurrent=1 and isdeleted=0)

if( @year=null or len(@year)=0)

set @year = year(getdate())exec ('if not exists(select * from timetableadjustments_'+@year+' where datefrom='''+@datefrom+''' and dateto='''+@dateto+''' and teacherid_onleave='+@teacherid_onleave+')

begin

insert into TimeTableAdjustments_'+@year+' (TeacherID_OnLeave,DateFrom,DateTo,UserID) values ('+@TeacherID_OnLeave+','''+@DateFrom+''','''+@DateTo+''','+@UserID+');

end')

else

set @flag=(select timetableadjustmentid from timetableadjustments_2007 where datefrom=@datefrom and dateto=@dateto and teacherid_onleave=@teacherid_onleave)

return @flag

--exec('select timetableadjustmentid from timetableadjustments_'+@year+' where datefrom='''+@DateFrom+''' and dateto='''+@DateTo+''' and teacherid_onleave='+@TeacherID_OnLeave+'

--')

--return @flag

--exec('@flag=select timetableadjustmentid from timetableadjustments_'+@year+' where datefrom='''+@DateFrom+''' and dateto='''+@DateTo+''' and teacherid_onleave='+@TeacherID_OnLeave+'')