ASP aspx file with multi-tab ajax panel and many controls on each panel.

I am developing a Webpage (.aspx) that contains a multi-tab ajax panel. Now, each of the tab panels contain several grids, textboxes, etc. As I am developing this page the code behind file aspx.cs is starting to get very large. At this point should I continue to add everything to this single page and code behind file or do something else?

Thanks,

Steve 

 
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