To make a non-modal or other dialog:
Add Resource - Dialog
Change the IDD and the title of the dialog
Set Tool Window to True for non-modal
Right click it, Add Class
Change base to CDialog
Remove DECLARE_DYNAMIC from header and IMPLEMENT_DYNAMIC from .cpp
Remove afxdialogex.h include
Change CDialog to CBaseDlg in .h and .cpp

Under DoDataExchange add:
  virtual BOOL OnInitDialog();
  virtual void OnOK();
  virtual void OnCancel();    (Not needed for modal if there is nothing to do)
And for non-modal:
  virtual void PostNcDestroy();
  virtual BOOL PreTranslateMessage(MSG* pMsg);
The latter is needed if there is any edit box

Also add a CloseWindow() as public if it is necessary to close the window externally
It can call OnOK, OnCancel, or DestroyWindow as needed.

In nonmodal, add to construction:
  mNonModal = true;

---------------------
BOOL CHoleFinder::OnInitDialog()
{
  CBaseDlg::OnInitDialog();

  SetDefID(45678);    // Disable OK from being default button for non-modal
  return TRUE;
}

These are the kinds of basic entries needed for nonmodal where placement is stored
void CHoleFinder::OnOK()
{
  OnCancel();    (For common closing actions to occur if any)
}

// Inform managing module of closing, or store placement and NULL out pointer
// right here
void CHoleFinder::OnCancel()
{
  //mWinApp->GetScreenShotPlacement();
  //mWinApp->mScreenShotDialog = NULL;
  DestroyWindow();
}

void CHoleFinder::PostNcDestroy()
{
  delete this;
  CDialog::PostNcDestroy();
}

BOOL CHoleFinder::PreTranslateMessage(MSG* pMsg)
{
  if (pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_RETURN)
    SetFocus();
  return CDialog::PreTranslateMessage(pMsg);
}

Probably OnOK should call CBaseDlg::OnOK, and OnCancel should call
CBaseDlg::OnCancel (although the latter might be problematic if OnOK calls
OnCancel, but this is not done universally
----------------------
Add class pointer and placement to managing module and functions to open
and get placement
Be sure to set the right IDD_ in the Create call.

Change font to Microsoft Sans Serif (it will change Use System font to False)

XXX Commit changes and push for editing at 120 DPI
Switch to 125% for editing at 120 DPI

NOn-modal dialogs have a problem with double validation of edit fields and you
need to use BaseDlg MinMaxInt and MinMaxFloat functions with the ID of the
field and a descriptor text.
  MinMaxFloat(IDC_EDIT_ACS_BEAM_SHIFT, m_fBeamShift, -10.f, 10.f,
    "Beam shift for centering");
Or better yet, replace the preceding DDX_Text too with DDX_MM_INT or DDX_MMF_LOAT