selectAll.change(()=> {
    var checked = selectAll.prop('checked');
    langs.prop('checked', checked);
    if(checked)
    {
        selectAllLabel.hide();
        deselectAllLabel.show();
    }
    else
    {
        selectAllLabel.show();
        deselectAllLabel.hide();
    }
});


invertSelect.click(()=>{
    for(var i = 0; i < langs.length; i++)
    {
        var checked = $(langs[i]).prop('checked');
        $(langs[i]).prop('checked',!checked);
    }
});

langs.click(()=>{
    for(var i = 0; i<langs.length; i++)
    {
          if(!$(langs[i]).is(':checked'))
        {
            selectAllLabel.show();
            deselectAllLabel.hide();
            selectAll.prop('checked',false);
            return;
        }
    }
    selectAllLabel.hide();
    deselectAllLabel.show();
    selectAll.prop('checked',true);
});