Packaging a magento module - how to get extension key options

When packaging a magento extension, how do you package in such a way where you get the extension key options in magento connect. i.e. the version 1.0 and 2.0 ?

The "Supported Releases" field is not a dropdown its a multi select. You need to select both options otherwise only one will be available.

Theres a good tutorial here: http://blog.chapagain.com.np/magento-how-to-create-extension-package-images/ - which walks you through the process.