Tableless split level design?

[sogj]

Okay, you know those websites that have a flash menu across the top that's centered at 800 pixels and the content is HTML below it? An example template is here:

http://www.templatemonster.com/website-templates/13452.html

1. How do you get the flash buttons to change the HTML page without reloading the flash page everytime and without using frames?
2. How do you get the entire page centered like that without using tables?

Thanks so much!
sogj