ptable.sample.middleclick.js

var block_clicks = function() {
    var isBlocked = !blockClick;
    blockClick = false;
    return isBlocked;
};

// The lightbox function first does:
e = e || event;
if (e.ctrlKey || e.shiftKey ||
    (e.which && (e.which === 2 || e.which === 3)) ||
    (e.button && (e.button === 4 || e.button === 2)))
    return;