How to change listbox content by changing other listbox

Dear All ,

I have a problem which made me crazy. i have a listbox in my form ( <form> not <CFFORM> ) and i want if anyone select an item from this listbox so i change the items in other listbox.

the point is second listbox item should come from database .

as an example :

first listbox contain country name :

     1- united arab emirates

     2- United state of America

     3- Islamic republic of Iran

When anyone selec one of the country , the cities should be retrive from the DATABASE "Countries" and table "CITIES",

i dont want to refresh the page, i seen in many pages work with ASP they have the same code , and when you change the country , the next listbox retrive the cities name from database and will change .

Thanks

Alireza Parsa