Creating ajax extender targeting RadCombobox

[Edwin]

I want to build an ajax control extender which targets a radComboBox.  When the combobox is changed, it reads the new value and then pass it to a web service to obtain a depended value from database.  Then the depended value will be put in another control, say a textbox.

The problem I encountered is that the target control inside my extender .js code lose the client api of the radcombobox.  For example, calling get_value() gives me error of unsupported method.  Is it possible to know the index of a radcombobox inside the array Telerik.Web.UI.RadComboBox.ComboBoxes?

Your advice is much appreciated.

Edwin

[Edwin]

I solved it by myself.  I need to use $find to get the control instead of directly using the targeted control.