DirectoryPress

I want to display a list of all USA states and cities on this page....http://wildlife.netsitesonline.com/directory/?type=location

How can i do this? Currently it only shows "USA" then you click on USA and it looks for listings.

When you click on USA, it should show all states in the USA, when you click on state, it should show the cities in that state.

I can add the data, just need help in displaying