js 获取目标网页源码

<script language="javascript">
//上移
 function getSource(url){
  var dex = url.indexOf("?");
  if(dex == -1){
   url = url + "?timestampt=" + new Date();
  } else {
   url = url + "&timestampt=" + new Date();
  }
  send_request(url, callbackGetSource);
 }
 function callbackGetSource(){
  if (http_request.readyState == 4) {
   if (http_request.status == 200) {
    var t = http_request.responseText
    alert(t);
   } else { //页面不正常
    alert("您所请求的页面有异常。");
   }
  }
 }
</script>

<!-- ajax -->
 <script language="javascript">
  var http_request = null;
     function send_request(url, method) {
      http_request = null;
      if(window.XMLHttpRequest) { //Mozilla 浏览器
    http_request = new XMLHttpRequest();
    if (http_request.overrideMimeType) {//设置MiME类别
      http_request.overrideMimeType('text/xml');
    }
      } else if (window.ActiveXObject) { // IE浏览器
    try {
      http_request = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
      try {
        http_request = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (e) {}
    }
      }
      if (!http_request) { // 异常，创建对象实例失败
    window.alert("不能创建XMLHttpRequest对象实例.");
    return false;
     }
   
      http_request.onreadystatechange = method;
     http_request.open("GET", url, true);
      http_request.send(null);
    }
    
 </script>

<input type="button" value="获取目标网页源码" onclick="javascript:getSource('http://m.weather.com.cn/data/101190201.html')">