In the sample above we have added two languages to the language dropdown. You can achive this using the "SupportedLanguages" property. The format is:
dictionary name,description,dictionary name,description
e.g.
<radS:RadSpell Runat="server" SupportedLanguages="en-US,English,fr-FR,French" ... />
The default selected language is the language set as the "DictionaryLanguage" property.