Instead of having the property to select single or multiple it would be more productive to have a property called SelectCount and we can enter the amount of listings to be selected. If its a single I select 1... for multiple I select how many I need. No more need for the Single/Multiple property except for backward compatibility.
I'm using ASP.Net AJAX RadAutoCompleteBox contrl. I can go throught the filtered items with 'up' and 'down' keys, but i want to select an item with 'TAB' key, is that possible?