I am trying to use this tutorial here: PHP Tutorial and I have a few questions.
1. What do you name the page that is using the script? index.html? index.php?

2. Where do you put the .php script files? Is it better to have them in their own folder? What kind of security should I put on them? If I put security on them then how do I get to them?

I am modifying the template for my own web page and I am not totally sure if I set it up right:
Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>Welcome to My Website</title>
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<link rel="stylesheet" type="text/css" href="style.css" />
</head>

<body>
<ul id="nav">
<!-- //How do I setup these links to load only the php page without reloading the entire thing? -->
 <li><a href="#" title="Home">Home</a></li>
 <li><a href="#" title="News &amp; Events">News &amp; Events</a></li>
 <li><a href="#" title="Services">Services</a> </li>
 <li><a href="#" title="Contact">Contact</a></li>
 <li><a href="#" title="Events">Events</a> </li>
 <li><a href="#" title="Forums">Forums</a></li>
 <li><a href="#" title="Login">Register</a></li>
</ul>
<!-- //This is the banner -->
<img src="images/banner.jpg" width="800" height="212" alt="temp" />

<!--  //This is the Date Time and Login -->
<form name="form1" method="post" action="checklogin.php">
<div id="Login" style="width: Auto">
	<input type="text" name="username" id="username"/>
	<input type="text" name="password" id="password"/>
	<input type="submit" name="Submit" value="Login">
	<!-- //When a user presses "Submit" then it should go to login.php -->
</div>
</form>
</html>
Any and all help is greatly appreciated!

D