二、如何通过URL获取其他网页源代码内容（火狐插件扩展开发教程）

content hcip chrome/content/

# Firefox
overlay    chrome://browser/content/browser.xul chrome://hcip/content/hcip.xul

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE overlay >
<overlay id="stockwatcher-overlay"
  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">

<!-- 引用我自己写的js文件，用来实现远程获取IP信息的功能 -->
<script type="application/x-javascript"
  src="chrome://hcip/content/hcip.js"/>

<!-- Firefox -->
<statusbar id="status-bar">
    <statusbarpanel id="hcip"
        label="点我获取地址"
        tooltiptext=""
        onclick="HCIP.getdz()"
    />
</statusbar>

</overlay>

var HCIP = {
    startup: function()
    {
        this.getdz();
    },
    
    getdz: function()
    {
        var samplePanel = document.getElementById('hcip');
        samplePanel.label = "加载中，稍等......";
        
        var httpRequest = null;
        var fullUrl = "http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js";

        function infoReceived()
        {
            var samplePanel = document.getElementById('hcip');
            eval( httpRequest.responseText );
            
            //获取地址信息
            var dz = remote_ip_info.country + " > " + remote_ip_info.province + " > " + remote_ip_info.city;
            
            //显示在状态栏上面
            samplePanel.label = dz;
            samplePanel.tooltipText = dz;
        }
        
        httpRequest = new XMLHttpRequest();
        //从新浪那边获取IP信息
        httpRequest.open("GET", fullUrl, true);
        
        //获取成功了，调用infoReceived方法
        httpRequest.onload = infoReceived;
        httpRequest.send(null);
    }
}

// 初始化
window.addEventListener("load", function(e) { HCIP.startup(); }, false);