How to populate Publication and components in an aspx page
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I created a Button on the ribbon "SelectCp".

OnClick of the button i am launching a custom aspx page.

Custom aspx page is having a dropdown with the items like.
1. Select CP
2. ETC

Now, when user will select the option "Select CP", i need to populate all the publication in a listitem on the aspx page, when user will select a publication i need to populate all the component in another listitem.Can anyone give an idea how to proceed.