How to create dropdowns that depend on other dropdowns

I have two dropdown on my form, namely state and town.if user select a state in a first dropdown, the second dropdown should be populated by all the town within the state. however the town of each state are arrange in column of spreadsheet so that the second dropdown can be  populate via towns on spreadsheet that corresponds to each state

You could use the All States and Cities widget: https://widgets.jotform.com/widget/all_states_and_cities 

Let us know if you need more help.