How to create/edit the backend interface of my custom plugin

I want to create a plugin which gives开发者_开发问答 the user the ability to include (on any page position) an image slideshow. The javascript thing and the frontend is working correctly (fetchs the images out of the db table)! But the backend "plugin form" looks just like this:

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Insert new Plugin: Image Slider

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My wish is an interface which allows the user to add new images and import them into the database and let the user select which image should be displayed on which page.. u know?

How can I produce such a backend config menu?

thank you

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Usually you can do this with FlexForms.