Thanks, I ask because it can be done differently in v4.
Sorry I don't know why you would get "Unable to get value of the property 'document': object is null or undefined" from the custom interface, but I would suggest
i) Don't set spellCheckButton.TextComponentInterface = TextComponentInterfaceType.Custom;
ii) Set spellCheckButton.TextComponentName to the ClientID of TBox, rather than the name - it's more reliable.
iii) Set spellCheckButton.FinishedListener="notifyDone" and spellCheckButton.FinishedListenerInformState=true;
<script type='text/javascript'>
function notifyDone(completed){
alert('Finished event captured spell check was complete '+completed);
}
</script>
You might also like (for server side)
http://keyoti.com/produc...ll%20Check%20Finish.htm
Here are the docs for v3 btw
http://keyoti.com/produc...ocumentation/Index.html
-Harry
-Harry