The context menu or the dialog used to display the spell checking result contains the main UI elements for the spell checker. To localize the context menu, modify the SpellChecker's IgnoreOnceMenuItemText, IgnoreAllMenuItemText, AddCustomMenuItemText, EndCheckerMenuItemText and NoSuggestionMenuItemText property. To localize the dialog, modify the dialog's ContentTemplate property. See Using SpellChecker with SpellCheckerDialog for more details.

SpellChecker also displays a message box when no spell error is found. The default message is in English. To customize this message, handle the SpellChecker's ClientSideOnMessage event. For example:

[ASPX]
<eo:SpellChecker ClientSideOnMessage="on_message" ...>
    ....
</eo:SpellChecker>

[JavaScript]
function on_message(control, name, message, args)
{
    if (name == "no_error")
        window.alert("Everything looks good!");
}