NodeJS Formidable Sockets

I'm trying to create a progress par using Formidable:

form.on('progress', function(bytesReceived, bytesExpected){
    percent = (bytesReceived / bytesExpected * 100) | 0;
        io.sockets.emit('progress', percent);
    });

This works fine. However io.sockets.emit will sent to ALL clients listening even if they are not the ones currently uploading. I'd like to broadcast to only that specific client.

Has anyone does this or know a better way? res.write does not appear to work either.

Thanks