how to match id in select database

Question

i select data from database 

 

select * from Tbl_Price where ProductId=@ProductId

 

 

and then

 

objAdmin.optnprice = "select";

objAdmin.Product_Id = Convert.ToInt16(Session["pid"].ToString());

objAdmin.SizeId = 0;

DataSet ds = objAdmin.Priceopreation(); 

 

store all data in ds

 

i want

 

when i will send size id  

 

objAdmin.SizeId = @SizeId ; 

 

then how to check   this sizeid in this store ds