Dropdown list box


I have a web page with 2 selection lists in a form. The contents of
the second selection list are updated based on the entry in the first
selection list.

For example:
if the first selection list has all the states in the USA, the second
list will display all the major cities in the selected state.

so if i select states then its show all the major cities of tat stats…

im doing this form in php…pls help me


Please check this thread for more explanation