Hai... iam new for C# ...im learning ..i created a table and showing it...now i want to update,edit and delete the records...i did it in my way...Problem is whenever i give save ,addnew or delete button it shows "Object reference not set to an instance of an object."this error at line 120 " cb.DataAdapter.Update(ds1.Tables["workers"]);"my program. using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms; namespace naag_database{ public partial c