Making a content type field dependent on another field

Rhythmyx Technical Discussion
1

In the workbench, I have a content type with two drop down fields (both sys_DropDownSingle): one for a source type and another for values for that source type. How do I make the second combo box dependent on the first one ?
For example, the first combo box may have two values: ‘country’ and ‘state’.

  1. When user chooses ‘country’, the second combo box should query a countries table. If the user chooses ‘state’, the second combo box should refresh and now point to a states table (AL, CA, GA…etc.). I am using version 6.7.0 - I don’t see a control available that can do that and the sys_DropDownSingle has no options to include dependency.

  2. I also want the second combo box disabled until user picks a value in the first one.

  3. In the ‘retrieve from table’ option, how can I provide a ‘where’ clause ?

Any help is appreciated.

Thanks.