System.NullReferenceException was unhandled
  Message=Referencia a objeto no establecida como instancia de un objeto.
  Source=FVH2011Secretaria
  StackTrace:
       en FVH2011Secretaria.impresionretrasadas.button1_Click(Object sender, EventArgs e) en D:\System Saver\Mis Documentos\Visual Studio 2010\Projects\FVH2011Secretaria\FVH2011Secretaria\impresionretrasadas.cs:línea 37
       en System.Windows.Forms.Control.OnClick(EventArgs e)
       en System.Windows.Forms.Button.OnClick(EventArgs e)
       en System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       en System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       en System.Windows.Forms.Control.WndProc(Message& m)
       en System.Windows.Forms.ButtonBase.WndProc(Message& m)
       en System.Windows.Forms.Button.WndProc(Message& m)
       en System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       en System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       en System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       en System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       en System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
       en System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       en System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       en System.Windows.Forms.Application.Run(Form mainForm)
       en FVH2011Secretaria.Program.Main() en D:\System Saver\Mis Documentos\Visual Studio 2010\Projects\FVH2011Secretaria\FVH2011Secretaria\Program.cs:línea 18
       en System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       en System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       en Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       en System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       en System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       en System.Threading.ThreadHelper.ThreadStart()
  InnerException: