dynamic build select box from server data

[dag78]

I am trying to create a form for users.
What I am trying to achieve is that when a user ticks a checkbox an optional dropdown list appears. Ideallt the dropdown list will just be greyed out until the check box is ticked.
I can create my list of checkboxes no problem, but I am at a lose as to how to create the drop down list and also get it to update a database link table at the same time.
the checkboxes are created from the database and the dropdown list options are also in the database?

How do i utilise the javascript/ajax to create this form?

The form does have other funcitons as well as this option and I have set up includes files with the funcitons in

Thanks in advance

Dave

[hsriat]

You can do that with Ajax. Have a look at this tutorial.
I hope it will help you.

[dag78]

It does a little, in the creation of the hidden field, but not with how to then add options from the database in the dropdown field, as I need the users to tick a checkbox, select an option and then insert those selected options into a table in the database