$(document).ready(function(){
  $.ajax({
        url: "/ajaxload/",
        type: "POST",
        cache: false,
        dataType: "json",
        success: function(data){
            $("#front_center_block_2 .content_wrapper").html(data.blocktop);
            $("#front_center_block_3 .content_wrapper").html(data.blockmiddle);
            $("#front_center_block_4 .content_wrapper").html(data.blockbottom);
        }
    });
});