private Workbook OpenManualFile() { string initialDirectory = String.Format(@"{0}\{1}\{2}", Path, RelativePath, "Original_Files"); Common.WriteToDebugWindow(String.Format(@"OpenFile: {0}", initialDirectory)); Workbook wb = null; wb = Globals.ThisAddIn.Application.Workbooks.Open( Filename: ExcelHlp.GetOpenFileName(initialDirectory), UpdateLinks: false, ReadOnly: true); if (wb != null) { pnlTask_OpenFile.BackColor = Color.Green; pnlTask_ConfirmAsOfDate.BackColor = Color.White;; } else { pnlTask_OpenFile.BackColor = Color.Red; } return(wb); }