how to create dynamic dependent dropdownlist using ODBC in LiveCycle?

I'm creating a user form using Livecycle designer.Here i'm not able to implement cascaded dropdownlist using javascript. I'm using ODBC dataconnection for data binding.Able to bind all data in respective dropdowns but don't know how to use cascading.

I followed this link LiveCycle ES2 * Adobe LiveCycle Designer ES2  but is is not working.