Data Grid and postback

 All,
  I have a simple .net c# form with a sqldatasource and a datagrid on it, in my code behind: I have this
SqlDataSource1.SelectCommandType =  SqlDataSourceCommandType.StoredProcedure;

SqlDataSource1.SelectParameters.Add("xxx", TypeCode.String, "Name");


SqlDataSource1.SelectCommand = "usp_xxx";