'To close an active workbook witout saving

ActiveWorkbook.Close SaveChanges:=False

'If the book to close is not active loop through work books
   For Each Book In Workbooks
       If Book.Name = "Name of Your Workbook.xls" Then
         Book.Close SaveChanges:=False
       End If
   Next

'to close the application
' Close the Application
    Application.Quit

'You'll need to check or ensure there are not more workbooks open before exiting the application. you can use workbook count

If workbooks.count > 1 Then
  msgbox "Hey dummy close the extra workbooks before clicking this button"
  Exit Sub
End If