基于js原生和ajax的get和post方法以及jsonp的原生写法实例: login.onclick = function(){ var xhr = new XMLHttpRequest(); xhr.open(get,http://localhost/ajax2/test2.php?username=+username.value+&pwd=+pwd2.value,true); xhr.send(); xhr.onreadystatechange = function(){ if (xhr.readyState == 4)