Inspecting the Right Alt key messages using Microsoft Spy++ returns the following:
WM_KEYDOWN nVirtKey:VK_CONTROL
WM_KEYDOWN nVirtKey:VK_MENU
WM_SYSKEYUP nVirtKey:VK_CONTROL
WM_KEYUP nVirtKey:VK_MENU
Why does the key generate 2 messages VK_CONTROL and VK_MENU? Why is the type of VK_CONTROL SYS (system) while VK_MENU non-system?