AutoTabs Center Panel url, application code layout basics

[javajunky]

I'm sure this is a simple question, but I'm puzzled as to what I should be doing with regards to code seperation, I could write everything as one big js file that was brought into a single page, is this the correct approach. To recap say I've an application that has multiple 'tabs' in the center region , where each tab has the responsibility to for doinging someting (its an admin console for want of a better word).

I'm happy in the understanding that I can create these tabs, by constructing an iframe with the src attribute set to be the url of a specific server page that populates a full html document, or I can create it with a div that just populates it with content. However with the former, I can't write Javascript that knows about my top level YUI-Ext 'application object [the object passed to YAHOO.ext.EventManager.onDocumentReady] and with the latter, I can't embed javascript that I can then use in this new tab, do I have to give the top level object knowledge of the whole application (i.e. use the JSBuilder app to create the mega-js file) ?

I'm sorry if this doesn't make total sense, but I can't find any examples [barring the feed viewer] where people have split out an app into different 'files' , where those files are different server side files, or javascript files :(

edit: I'm sorry this should've been posted in the help forms, not this forum, could someone please move it for me ! :(

[Animal]

Design your UI in an OO manner, and put the javascript objects that you use in seperate files for ease of code maintenance. You can concatenate them during the build process and load on big js file.

If it's a single page app, this should be OK.