I see you are using our RadSpellChecker in a very interesting way. Luckily our SpellChecker exposes a convenient API. In fact the default dialogs have been built entirely using this API. We are sending you an example where there are a RadRichTextBox and a custom spellchecking UI on a page. Of course you can style it, use entirely different controls or anything else that you can think of.
The demo we are sending you first checks if there is an error (your second question) and then if there is, populates the listbox. After that you can choose a word and replace the wrong one.
Please review the demo-project and tell us if that helps you. We are looking forward to your reply.
the Telerik team
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