http://webpresence.qq.com/getonline?Type=1&1617052138: 判断腾讯QQ是否在线接口.
下面是个简单的例子:
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<script>
var online= new Array();
</script>
<script src="http://webpresence.qq.com/getonline?Type=1&1617052138:"></script>
<script type="text/javascript">
if (online[0]==0){
document.write("<a href=‘tencent://message/?uin=1617052138&Site=1111&Menu=yes‘><img border=0 src=‘images/qq02.jpg‘ alt=QQ不在线，请留言></a>");
}
else{
document.write("<a href=‘tencent://message/?uin=1617052138&Site=1111&Menu=yes‘><img border=0 src=‘images/qq01.jpg‘ alt=QQ在线交谈></a>");
}
</script>
</head>
<body>
</body>
</html>
原文：http://www.cnblogs.com/liubeimeng/p/4064843.html