A simple method

<script language="JavaScript">
<!--
var password = prompt("What's the password","Type password");

if (password == "yes")
{
alert("Welcome");
} else {
alert("Sorry wrong password");
javascript:history.back()
}
-->
</script>


=======================================
An encrypted password method

Go here to generate encrypted login for this method:

	http://www.dynamicdrive.com/dynamicindex9/password.htm

Step 1: First, generate the encrypted username/password set by typing the desired selections in the box at above address and press calculate (the generator is NOT case sensitive).

Username: customer
Password: froula861

Username Encryption: 21525467268796920
Password Encryption: 234415983393236740

Step 2: Once you have the encrypted set, name the secure page what your password is .htm (i.e. "froula861.htm"). Then, add the following script to the page leading up to the protected one (the login page), replacing the numbers inside the script (where indicated by the comments) with the numbers generated above:

Script:

===

<script>
//Encrypted Password script- By Rob Heslop
//Script featured on Dynamic Drive 
//Visit http://www.dynamicdrive.com 

function submitentry(){
password = document.password1.password2.value.toLowerCase()
username = document.password1.username2.value.toLowerCase()
passcode = 1
usercode = 1
for(i = 0; i < password.length; i++) {
passcode *= password.charCodeAt(i);
}
for(x = 0; x < username.length; x++) {
usercode *= username.charCodeAt(x);
}
//CHANGE THE NUMBERS BELOW TO REFLECT YOUR USERNAME/PASSWORD
if(usercode==21525467268796920&&passcode==234415983393236740)
//CHANGE THE NUMBERS ABOVE TO REFLECT YOUR USERNAME/PASSWORD
{
window.location=password+".htm"}
else{
alert("password/username combination wrong")}
}
</script>

<form name="password1">
<strong>Enter username: </strong>
<input type="text" name="username2" size="15">
<br>
<strong>Enter password: </strong>
<input type="password" name="password2" size="15">

<input type="button" value="Submit" onClick="submitentry()">
</form>

===

You're done.

Let's replay everything, just to make sure everyone's on the same page:

Step 1: Use the generator to create the encrypted, numeric versions of your username/password (ie: "good" becomes 126906300)
Step 2: Name the page you wish to password protect what your password is, prefixed with .htm (ie: "good.htm")
Step 3: Inside the code of Step 2 above, change the two numbers to the numbers generated by the generator
Step 4: Finally, insert the code of Step 2 into the proceeding page visitors will login using.