If I set the data value field I do not get the data I need.
I created a new example, much closer to what I am doing. http://dojo.telerik.com/agATe
If you visit that link and add The Dark Night to the list, a warning will pop up. I'd also like the user to add custom items to that multi select but if they are added then the warning will also popup. This is almost working - if you type a movie not in the list ('test') then you will see the custom no data template. Clicking the button does add the item to the data source but does not select it. The user has to open the multi select again, select the new custom item again, and then it will persist and the warning message show.