只能測到瞬時速度，不是很準確
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title> New Document </title>
<meta http-equiv="Content-Type" content="text/html; charset=gbk"/>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="xinmingyang">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<body>
<SCRIPT language=JavaScript>
var st = new Date();
</SCRIPT>
<IMG alt="測試圖片" src="http://sp2.yokacdn.com/photos/f3/4f/702018/photo_322092_500.jpg" οnlοad="showspeed();">
<div id='showtxt'></div>
<script>
var arr=["網速低於50KB","網速在50-100KB之間","網速在100-200KB之間","網速在200-300KB之間","視頻通訊"];
function showspeed()
{
var filesize =35.4; //measured in KB
var et = new Date();
var speed = Math.round(filesize*1000)/(et - st);
document.title=speed;
var scope=(speed>0 && speed<=50)?0:(speed>50 && speed<=100)?1:(speed>=100 && speed<200)?2:(speed>=200 && speed<300)?3:4;
alert(scope)
document.getElementById("showtxt").innerHTML = ("您的下載速度爲：" + arr[scope] + " (K/秒)")
}
</script>
</body>
</html>
