Mouse double click not working for MDI view scrollbar

[vinodpj]

I have an old MDI application created using SDK method.
Its main view is having scrollbar.

On double clicking on the vertical/horizontal scrollbar, I am able to receive only one click. (Second click is missing. )
That is the vertical scrollbar is getting moved only once. I am not receiving the second mouse click . (ie OnVScrollbar() function is getting called only once.).

And in the MDIWindowProc() function I am handling WM_VSCROLL,WM_LBUTTONDOWN, WM_LBUTTONDBLCLK functions.

Can anyone you please tell me which other function should I subcribe for moving vertical scroll bar twice during mouse double click.


Code snippet used for creating the view is given below

// Register the MDI child class
	wc.style	= CS_DBLCLKS | CS_OWNDC;
	wc.lpfnWndProc	= MDIWndProc;
	wc.hInstance	= _hInst;
	wc.cbClsExtra	= 0;
	wc.cbWndExtra	= MDIWNDEXTRA;
	wc.hbrBackground= (HBRUSH)(COLOR_WINDOW + 1);
//	wc.hbrBackground= COLOR_APPWORKSPACE + 1;
	wc.hIcon	= LoadIcon(_hLib, ID(IDI_ICON1));;
	wc.hCursor	= NULL;
	wc.lpszMenuName	= NULL;
	strcpy(szClass, _szPropertyName);
	strcat(szClass, "MDI");
	wc.lpszClassName= szClass;
	if (!RegisterClass(&wc))
		return FALSE;