Informs MSHTML that a rectangular area of a rendered behavior should be redrawn.
HRESULT retVal = object.InvalidateRect(prcInvalid);
Pointer to a variable of type RECT that contains the bounds of the area to be redrawn.
If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
The coordinate-system origin for this rectangle is the top-left corner of the element to which the behavior is attached.
A call to this method causes MSHTML to call IHTMLPainter::Draw.
Setting prcInvalid to NULL causes the entire element to be redrawn.