Related dropdown fields

Related dropdown fields

I have the following master table of States and Cities. How do I insert related fields in another form, so when the State is selected, only those cities in that particular state are displayed in the City field. Currently the lookup fields in separate forms show all states and cities.
State
City
California
LA
California
San Diego
California
San Francisco
California
Fresno
Florida
Jacksonville
Florida
Miami
Florida
Orlando