How to avoid a correct instruction to be detected as error in NetBeans?

I'm developing a little socket.io and node.js system using NetBeans 7.2 as my IDE.

I'm finding myself running with an error highlight every time I write a perfect correct instruction like:

io.sockets.in(channel_id).emit('new user', data);

Precisely, the ".in" part is what bothers NetBeans (I guess because 'in' is a reserved javascript word). The error I'm getting is "missing name after . operator"

Is there any way I can disable this particular syntax error? (I want the other errors to be highlighted, so I don't want to disable all error checking)