function get_json(data) {
    return eval('(' + data + ')');
}
$(function(){
        $("#next").click(function() {
            url = $("#next").attr("href")
            last = $("#last").attr("value")
            $.ajax(
            {
            type: 'POST',
            url: url,
            contentType: 'text/html',
            dataType: 'html',
            data: {'last': last},
            success: function(data2) {
                json = get_json(data2)
                $("#category_thumbnails").replaceWith(json.html)
                }}
            )
            return false
    })
        $("#before").click(function() {
            url = $("#before").attr("href")
            last = $("#last").attr("value")
            $.ajax(
            {
            type: 'POST',
            url: url,
            data: {'last': last},
            success: function(data) {
                json = get_json(data)
                $("#category_thumbnails").replaceWith(json.html)
                }}
            )
            return false
    })
})