Wordpress 2.9 theme options admin page with image upload

I am creating a theme options page for my wordpress 2.9 theme and I wanted to include a field where I can upload a different logo. So far I've added textareas, inputs and checkboxes, bu开发者_如何学JAVAt I'm not sure how to upload an image. Does anyone Know of a tutorial that explains how to do this or can anyone offer some insight?

Thanks for the help.

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This post describes a way of adding an upload field: http://web.archive.org/web/20100408201208/http://www.wptavern.com/forum/13306-post10.html