persistCustomValues Property

enables / disables persisting of custom values. If some value that doesn't exist in the list is typed, and we remove the focus from the control, a new item is created, and marked IsCustom=true, and persisted to the server persisting of custom values SHOULD NOT be enabled along with loadOnDemand or Paging ! or with enables / disables persisting of custom values.

Syntax

ASP.NET Ajax Javascript (Specification)
function get_persistCustomValues() : Boolean

ASP.NET Ajax Javascript (Usage)
var resultVar = instanceOfWebDropDown.get_persistCustomValues();