Dynamic dropdown menus

I am trying to build dynamic dropdown menus with Javascript. There are supposed to be 3 menu boxes. After the 1st one is chosen, the 2nd one is dynamically populated based on the 1st choice, and then the 3rd one is based on the 2nd choide. I know how to do this by hard coding the menu choices. Could someone show me a similar example where the menu choices are pulled from a database table using ColdFusion, please?

Thanks in advance!

Tracy Xia