e621 swimmer v2

// ==UserScript==
// @name             E621 Swimmer
// @description      Navigate e621's pools with arrow keys
// @include          http*://e621.net/post/show/*
// @grant            none
// ==/UserScript==

var tags = jQuery.find('a')
//I do a.length/2 because I'm assuming it will be in
//the first half of the page. I don't want to have to loop over
//every link if it's not there
for(var i = 0; i < tags.length/2; ++i) {
    if(tags[i].innerText === '<< Previous') {
        var prev = tags[i].href;
    }
    else if(tags[i].innerText === "Next >>") {
        var next = tags[i].href;
        break
    }
}
document.addEventListener('keydown', function (e) {
    if (e.keyCode === 37 && prev != null) {
        window.location = prev;
    }
    else if (e.keyCode === 39 && next != null) {
        window.location = next;
    }
}, false);