Looking at your script you will need to do ALOT
first i would say put all your content into a div and use the css:
margin: auto 0;
or is it margin: 0 auto;
im not sure.
in yor script you are using css #center to reference to somehing that doesn't exist
to reference to a <center> tag you simply use center in your css
using a # is refereing to something like <div id='center'>
and using a . is to a class <div class='center'>
i would use something like..
<html>
<head>
</head>
<body>
<div id='page-wrap>
<!-- Content in here -->
</div>
</body>
</html>