代碼如下所示：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>密碼保護相應頁面</title>
</head>
<body>
<SCRIPT LANGUAGE="JavaScript">
function password() {
var testV = 1;
var pass1 = prompt('請輸入密碼(密碼是shenlong):','');
while (testV < 3) {
if (!pass1)
history.go(-1);
if (pass1 == "shenlong") {
alert('密碼正確!');
break;
}
testV+=1;
var pass1 =
prompt('密碼錯誤!請重新輸入:');
}
if (pass1!="password" & testV ==3)
history.go(-1);
return " ";
}
document.write(password());
</SCRIPT>
</body>
</html>