Calculate LabelIds against Label field Id in AX2012 using X++

I have calculated a total number of label id's against Label file id . In my case Label file Id is "NVS".

static void maxLabelIds(Args _args)
{
    SysLabel   SysLabel;
    int maxLabelId;
    ;
    SysLabel =  new SysLabel('EN-US');
    maxLabelId = SysLabel.maxLabelId('NVS');
    print maxLabelId;
    pause;
}