cake php, how to populate a drop down selection based on another drop down selection?

Question

I have a table something like this:

id  test   attr  dim
1   test1  a1    d1
2   test2  a2    d2
3   test3  a1    d3
4   test3  a1    d2

I am c

Answer 1

You can do with help of ajax->observefield

eg:

$options = array('url' => 'getcounties', 'update' => 'ExampleCountyI
$ajax->observeField('ExampleStateId', $options);

UPDATED

observeField is not more available in CakePHP js helper here it's equivalent way to the same for newer CakePHP version >= 2.x