[ArmagedDance]

$.ajax({
    url: "session_editor.php",
   	type: "post",
   	dataType: 'json',
   	data: querystringonline,
   	beforeSend: function (){
   	},
   	success: function(data){
            var clients=data.clients_fio;

$('#clients_fio p').append(data.clients_fio);
	},	
   	complete: function(){
   	}
   });

clients_fio - вложенный массив