I have the following form, submitted by AJAX:
HTML
<form class="form-horizontal" id="formEditUsername" action="<?php echo URL; ?>account/editusername_action" method="post">
  <input type="text" class="form-control" name="user_name" id="user_name" placeholder="Add username" value="User ">
  <button type="submit" class="btn btn-default">Save</button>
</form>
AJAX
$("#formEditUsername").submit(function(event){
        //disable default click operation
        event.preventDefault();
        var action_url = $(this).attr("action");
       $(".help-block.username").hide().html("<i class='fa fa-refresh fa-spin'></i>   Processing...").fadeIn('slow');
       console.log(action_url);
       var postData = $(this).serializeArray();
        //console.log(postData);
        $.post(action_url,postData,function(data){
            console.log(data);
            var obj = $.parseJSON(data);
            $(".help-block.username").html("Saving...");
            if(obj.status == "error")
            {
            $(".help-block.username").css({color: '#990033'});
            $(".help-block.username").html(obj.message).fadeIn('slow');
            };
            if(obj.status == "success")
            {
                $(".help-block.username").css({color: '#00b25a'});
                $(".help-block.username").html(obj.message).fadeIn('slow');
                $(".namebox").html(obj.username);
            }
        });
    });  
I want to add a feature so that the form submits with focusout(), after the input (#user_name) loses focus. Any ideas?