<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html> <head> <title>Ajax Hello World</title> <script type="text/javascript"> var xmlHttp; function createXMLHttpRequest(){ if(window.ActiveXObject){ xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } else if(window.XMLHttpRequest){ xmlHttp = new XMLHttpRequest(); } } function startRequest(){ createXMLHttpRequest(); try{ xmlHttp.onreadystatechange = handleStateChange; xmlHttp.open("GET","data.txt",true); xmlHttp.send(null); }catch(exception){ alert("您要访问的资源不存在!"); } } function handleStateChange(){ if(xmlHttp.readyState == 4){ if (xmlHttp.status == 200 || xmlHttp.status == 0){ // 显示返回结果 alert("responseText's value: " + xmlHttp.responseText); } } } </script> </head> <body> <div> <input type="button" value="return ajax responseText's value" onclick="startRequest();" /> </div> </body> </html>