checking PAN No is already present or not if (!string.IsNullOrEmpty(Convert.ToString(ViewState["UserpanID"]))) { if ( CheckPannoExistOrNot (txtpanno.Text.Trim())) { sb.Append("Pan No Is Already Exists"); lblpanError.Text = sb.ToString(); sb.Clear(); txtpanno.Text = string.Empty; return; } } Private bool CheckPannoExist...