Video function on ML Comand unit

[Bradshaw]

Can someone please help me? I have a 2006 ML320 CDi Sport and i stay in the UK. I have the Comand system fitted with the DVD Sat Nav and the system has a 'Video' key on it? Nothing happens when you press it.....can someone explain the point in it? I've tried inputting ordinary DVDs but it doesnt work. Would appreciate someone giving me an explanation...

Thanks in advance.