void SizeGrip::LeftDown(Point p, dword flags)
{
	TopWindow *q = dynamic_cast<TopWindow *>(GetTopCtrl());
	if(!q || q->IsMaximized() || !q->IsSizeable()) return;
#ifdef PLATFORM_WIN32
	HWND hwnd = q->GetHWND();
	p = GetMousePos() - q->GetRect().TopLeft();
	if(hwnd) {
		::SendMessage(hwnd, WM_SYSCOMMAND, 0xf008, MAKELONG(p.x, p.y));
		::SendMessage(hwnd, WM_LBUTTONUP, 0, MAKELONG(p.x, p.y));
	}