Dynamic dropdownlist in PHP

Hi Friends.......................


I know concept of dynamic dropdownlist in PHP. But I have some problem which is as follows

There are three dynamic dropdownlist in a form in PHP. The name of first dropdownlist is country, second is state abd  third is city. There are three tables in MySql database i.e. tbl_country, tbl_state, tbl_city.

I want dropdownlist 1 shows the whole country name which is in the tbl_country. When we select any country from dropdownlist then state of selected country will show in the second dropdownlist and when we select any state from second dropdownload then city of selected state will show in the third dropdownlist ?

Please help me anyone ?




Thanks.....