DWORD GetMenuCheckMarkDimensions()
This function returns the dimensions of the default checkmark bitmap. Windows displays this bitmap next to checked menu items. Before calling the SetMenuItemBitmaps function to replace the default checkmark, an application should call the GetMenuCheckMarkDimensions function to determine the correct size for the bitmaps.
This function has no parameters.
The return value specifies the height and width of the default checkmark bitmap. The high-order word contains the height in pixels and the low-order word contains the width.