am o procedura stocata pe care o apelez din asp.net unde am un grid

problema mea e ca nu stiu cum imi trimite parametrul adica ce tipp il face

procedura arata asa

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

ALTER proc [dbo].[sp_up_masini_Casco]
@id numeric(18,0), @id_masina numeric(18,0), @data_asig1 nvarchar(20),
@data_asig datetime,@data_exp datetime,
@data_exp1 nvarchar(20),
@suma nvarchar(18), @val nchar(10), @prima numeric(18,2), @soc_asig
nvarchar(10), @procent numeric(18,2)
as

set nocount on
declare @tableOneCount int
declare @sum nvarchar(20)
declare @prim nvarchar(20)
declare @proc nvarchar(20)


begin
    -- Get the number of rows from the first table
    SELECT @tableOneCount = (SELECT COUNT(*) FROM tblMasinaCASCO
                         WHERE id_masina=@id)
-- set @sum=substring(@suma,1,len(@suma)-3)+'.'+substring(@suma,len(@suma)-1,len(@suma))


if @tableOneCount=0

insert into tblMasinaCASCO(id_masina,data_asig,data_exp,suma,val,prima,soc_asig,procent)
  values(@id,convert(datetime,@data_asig1, 104),convert(datetime,@data_exp1,104),@sum,@val,@prim,@soc_asig,@proc)
 
else
 
   
    update tblMasinaCASCO set id_masina =@id ,
        data_asig = convert(datetime,@data_asig1, 104),data_exp = convert(datetime,@data_exp1,104),
        suma = substring(@suma,1,len(@suma)-3)+'.'+substring(@suma,len(@suma)-1,len(@suma)),val=@val,
        soc_asig = @soc_asig,procent=@proc
       where  id_masina = @id
 
end

cum pot adauga un breakpoint? sau cum pot afla cand o valoarea parametrului suma?