<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <title>12</title> <script src="ajax.js"></script> <script> window.onload=function () { var oBtn=document.getElementById('btn1'); oBtn.onclick=function(){ ajax('aaa.txt', function (str) { alert(str); },function(){ alert('失败'); }); } } </script> </head> <body> <input id="btn1" type="button" value="读取"/> </body> </html>