DataGrid

Im not sure what your saying in (2) your english isnt too great, can you try and re-phrase
1) you'll need a business object/business data to manage the data within your DataGrid. Its always nice to keep the logic seperate. Im not sure how your doing it, but here is a technique by which data is added to and managed within a DataSet object. Your can then use this to manipulate your data and bind it to your grid.

// Init...
DataRow newRow = null;
DataSet ds = new DataSet();

// Setup table and columns...
ds.Tables.Add("items");
ds.Tables["items"].Columns.Add("Column 1");
ds.Tables["items"].Columns.Add("Column 2");

// Add new data row data
newRow = ds.Tables["items"].NewRow();
newRow["Column 1"] = "value";
newRow["Column 2"] = "value";
ds.Tables["items"].Rows.Add(newRow);


// Bind it up to datagrid
DataGrid1.DataSource = ds;
DataGrid1.DataBind();