I had no problem inserting the youtube code. What, exactly, was/is the errors you're getting?

If you want to create a separate page (which is what I did) search the forums for "php include" and you'll find all kinds of goodies posted about creating pages.

This code will require people to be logged in:

Code:
<?php
session_start();
require("include/config.php");
require("include/function.php");
STemplate::display('header.tpl');
if (!isset($_SESSION['USERNAME'])) {
   Header("Location: {$config['baseurl']}/login.php");
   print "
<span style=\"text-align:center\"><h1>PUT YOUR PAGE TITLE HERE</h1></span>
";
   print "<div style=\"border:1px solid #FF0000;background-color:#FF9999\"><span style=\"text-align:center\"><h3>You must be logged in to use this section of our site. <a href=\"../login.php\">Please Log in here</a>.</h3></div>

";
STemplate::display('footer.tpl');
        exit(0);
} 
?>

INSERT YOUR YOUTUBE OR OTHER HTML CODE HERE TO YOUR HEART'S CONTENT. KNOCK YOURSELF OUT!!!

<? STemplate::display('footer.tpl');?>
save this as whatevernameyouwant.php and put it in the root directory and link to it from your header.tpl

If you don't want to require login to view the page then use this code at the top which is found here viewtopic.php?f=8&t=1155

Code:
<?php
session_start();
include("include/config.php");
include("include/function.php");
STemplate::display('header.tpl');
include("pages/links.html");
STemplate::display('footer.tpl');
?>
Here's some additional references viewtopic.php?f=8&t=1155 Again, just search the forums for "include php" and "add pages" "insert java" and stuff like that. For scripts, sometimes you have to add {literal} javacode here{/literal} depending on where, in the templates, you're sticking in the code, and there is also the buyscripts.in wiki here http://docs.buyscripts.in/Main_Page