A number of web browser plug-ins are available to automatically check spelling for whatever you type while using that browser, whether in the Databank or other web pages.  Some of our staff have used iespell, which works on Internet Explorer.  Just do a web search like "spell check download for Safari" to find one that works on your preferred browser.

I use Google's Chrome browser, which has a built-in spell check as an optional setting.  It's a little flaky though - for example, it does not like the word "Databank!"