Unable to use the voice commands

[serbarry]

I have already opened this topic in the GS450H section of the forum and I am looking for help from owners of my same model or same generation: in my 2008 GS450H I am unable to use the voice commands: each time I press the button on the steering wheel for the voice commands, a voice message tells me that if I want to dial a number from the phone book I need to say: "dial by name". So I say it, and the voice message asks me to say the name. But when I say the name saved in the phone book, the voice message says: "name tag empty". I have looked in the manual but I have not found anything about saving a name tag while in the PDF manual saved in my laptop there's a procedure for saving a name tag, but it doesn't work. Does anybody know what I am doing wrong? Thank you