This, as you can see, is VERY usefull for places that won't allow their users CGI access. You can remove the prompt to type in please from the script. The only fallback is that the person can see the page reloading while he's going to the different URL. You can make it more fail-proof; but it would be longer and considering how JS&HTML-literate most on the internet users are, they wouldn't know what to look for.
The source...

<script language="Javascript">

var password = prompt("Enter in the password \(It's 'please'\)")

if (password.toLowerCase() == "please") {
alert("Come right in \n \n You've entered in the right password")
location = "right.html"

else {
location = "wrong.html"