delete from gride

السلام عليكم ورحمة الله

اقوم بعمل web user control

لعمل بحث فى قاعدة البيانات المشكلة التى تواجهنى هى عند الحذف يظهر لى هذا الخطأ

وهذا كو الحذف

 protected void btnremove_Click(object sender, EventArgs e)
        {

            m.Unsubscribe(grid.SelectedRow.Cells[1].Text);
            btnremove.Enabled = false;
            grid.DataBind();
            lblmessage.Text = "User Deleted Successfully" ;
        }
 

وهذا باقى الكود واللى فيه مشكلة

 //Run Connection
        private int Connection()
        {
         //DB work
            conn.Open();
            try
            {
            int x=comand.ExecuteNonQuery();
            conn.Close();
            return x;
            }
            catch(SqlException ex)
            {
                conn.Close();
                return ex.Number;
            }
        }

        //insert Or Update Or Delete Opration
        public int RunUpdate (string IUD)
        {
            //sent to me text operation i(nsert Or Update Or Delete Opration)
        Intialize(CommandType.Text,IUD);
            return Connection();
        
        }
        
        public DataTable RunQuery (string select)
        {
            //select opretion
            Intialize(CommandType.Text,select);
            tbl =new DataTable();
            conn.Open();
            tbl.Load(comand.ExecuteReader());
            conn.Close();
            return tbl ;
        }
        
        public int RunProcedure(string ProcedureName,SortedList ParaVal)
         {
           Intialize(CommandType.StoredProcedure,ProcedureName);

            //add paramater by for loop
            //get parameter name by paraval .getkey
            //get value by index
           for (int x = 0; x < ParaVal.Count; x++)
           {
               comand.Parameters.AddWithValue(ParaVal.GetKey(x).ToString(), ParaVal.GetByIndex(x).ToString());

           }
           return Connection();
         
           
            }