$(document).ready(function() {
    document.onkeydown = function()
	{
	    var j = event.keyIdentifier
	    if (j == "Right")
		window.location = nextUrl
	    else if (j == "Left")
		window.location = prevUrl
		}
	   });

$(document).ready(function() {
	    var nextPage = $("#next_page_link")
	    var prevPage = $("#previous_page_link")
	    nextUrl = nextPage.attr("href")
	    prevUrl = prevPage.attr("href")
	});