<html>
<head>
<title>声明一个自定义的函数</title>
</head>
<body>
<script language="javascript">
<!--
function sum(n){
s = 0;
for(i=1;i<=n;i++){
s+=i;
}
return s;
}
document.write("1~10相加的结果为:",sum(10),"<br>");
document.write("1~100相加的结果为:",sum(100));
//-->
</script>
</body>
</html>