AJAX Dodaj edytuj rekordy Usuń w bazie danych za pomocą PHP

function callCrudAction(action,id) {
	$("#loaderIcon").show();
	var queryString;
	switch(action) {
		case "add":
          queryString = 'action='+action+'&txtmessage='+ $("#txtmessage").val();
          break;
		case "edit":
          queryString = 'action='+action+'&message_id='+ id + '&txtmessage='+ $("#txtmessage_"+id).val();
          break;
		case "delete":
			queryString = 'action='+action+'&message_id='+ id;
			break;
     }	 
jQuery.ajax({
  url: "crud_action.php",
  data:queryString,
  type: "POST",
  success:function(data){
  switch(action) {
    case "add":
      $("#comment-list-box").append(data);
      break;
     case "edit":
      $("#message_" + id + " .message-content").html(data);
      $('#frmAdd').show();
      break;
    case "delete":
      $('#message_'+id).fadeOut();
      break;
  }
$("#txtmessage").val('');
$("#loaderIcon").hide();
},
});}
Rht