callback.js

var my_callback_div = $('<div>'),
    global_var;
my_callback_div.on('my-object-event', function (e, object) {
   console.log(object);
   global_var = object;

   // do your thing
});


function display_obj(obj, category) {
    var url = "/" + category + "/" + obj.val();
    console.log(url);
  
    $.get(url, function(resp) {
        var rows = "";
        for (var key in resp) {
            console.log("Generating pairs[" + key + "]: " + resp[key]);
            rows += generate_row(key, resp[key]);
        }
        $("#form").empty();
        $("#form").html(rows);
        $("#message").empty();
        
        my_callback_div.trigger('my-object-event', [resp]);
    });

}