Programming Forums - CSS is lost when I change Dreamweaver html tag to accomodate Javascript

I have a hidden thumbnail of an image that appear upon rollover of text within my document. The thumb is supposed to appear in the immediate general area below the text. Within my include file (without html, title, head and body tags), it wrks great! However the minute I open the include within the page (with the tags), the position is random and no where near where it is supposed to be. I have stripped the page of all code piece-by-piece (took a while), and the reason it is having these problems is this code here:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
</head>

Here are two pages:
http://d17409300.r229.radiowebworks....sting00121.php
http://d17409300.r229.radiowebworks....sting00122.php

The first contains that code, the second contains this:

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
</head>

The problem is that for whatever reason, with the second code, I lose my css on the links and it alters the page. How can I fix this problem? Please advise asap, as I have wasted WAY to much time trying to figure this out!

Thanks so much, Everyone! I truly appreciate it!

Sincerely-
Charles Carter