How to limit a dialog's width while dragging the edge?

Hello,

I am using Visual Studio 6.0 and I'd like to know how can I block the
resizing of
a dialog's width when it reaches a certain minimum?

I am currently using the CMyDlg::OnSize() message handler to do the following:

void CMyDlg::OnSize(UINT nType, int cx, int cy)
{
    CDialog::OnSize(nType, cx, cy);

    CRect rect;
    GetWindowRect(&rect);
    if (rect.Width() < 300)
    {
        rect.right = rect.left + 300;
        MoveWindow(&rect, TRUE);
    }
}

This works but it is really ugly because say I drag the dialog's right edge
to the
left, when the width becomes less than the minimum (300) the dialog keeps
drawing the right edge at the mouse position then updates it to have a width
of 300.

How can I fix this to make it behave like the Notepad window for example. If
you
open Notepad than try to drag its window's right edge all the way, you'll
notice
that at a ceratin point it will block. This is exactly what I want to achieve.

I really appreciate any help for this.

Thanks,

Geo