Как бы уязвимость
script var login = Object(); function login_status(a, b) { div = document.createElement('div'); if (b == 1){ div.innerHTML = a + ': logged in'; div.style.color = 'red'; } else { div.innerHTML = a + ': not logged in'; div.style.color = 'green'; } document.body.appendChild(div); }; function img(a, b) { var i = new Image(); i.onload = function () { login_status(b, 1); i = i.onload = i.onerror = undefined }; i.onerror = function () { login_status(b, 0); i = i.onload = i.onerror = undefined }; i.src = a };