Can anyone recommend how to implement a cascading drop down box function, such as the one demonstrated in the following link:

s demonstrated in the link, I too require the need for a three tier drop down system, with the user selecting textual options in the drop down boxes and allow for the correspinding index be stores as the selection.


Hi Robbie,

It's easy to achieve that behavior. Should be something like this:

Add 3 combo boxes, give names to all 3.
On the preparation do a query to get the values of the first one and assign it as the source for the 1st combo.
Create 2 recordlist variables (of the correct types of the data you want them to select) in your screen and assign them to the 2nd and 3rd combo boxes.
Then in the On Change of the 1st combo, call a screen action. In there use the variable associated to the 1st combo to do a query and assign the result of your query to the recordlist you used on the 2nd. Do a Ajax Refresh of the 2nd combo.
Repeat for the 2nd->3rd with a different screen action.

Also to do that disabled behavior use the a expression with the correspondent recordlist List.Length <> 0 in the "Enabled" property

João Rosado


Thanks for providing the link.

Suraj B