Drupal won't let JQuery add to a select list in a custom form

I have a form with a drop-down 'select' element that the user will sometimes need to add to. So, I added a link to open a Modal Frame form, created the Modal Frame form, and made its _submit() function add the new data to the table that holds options for the select element. Then it开发者_开发问答 "returns" the new ID and name to the Javascript callback (the way Modal Frames do), and the JS callback adds the new element to the dropdown, and makes it the currently selected element in the browser, with JQuery. This all works great.

Finally, the user submits the original form, and gets the error "An illegal choice has been detected. Please contact the site administrator."

The form building function creates the option list from the database, which (I checked) DOES include the new option, so I'm guessing Drupal is using a cached version of the form rather than re-building it before it does the automatic validation. If you go back one page, then forward, the newly-added choice is there in the list.

I tried adding:

global $GLOBALS;
$GLOBALS['conf']['cache'] = FALSE;

to the function that builds the page with the problem, but it made no difference.

FYI: this is part of a multi-page form, if it matters.

I also thought about trying to add the option to the cached version of the "parent" form in the "child" form _submit() function, but don't know how to get the form_build_id of the "parent" form. Besides, that seems like way too much of a kludge (though I could be wrong about that).

Ideas?

You are submitting the form which is different then the time of form render so Drupal consider it as malicious input. If you want to skip that malicious check then add below line as property of your form in your_module_form() function.

'#DANGEROUS_SKIP_CHECK' => TRUE,

This will solve your problem but make sure that you are adding manual validation to protect from malicious inputs :). Hope this will help you.

I think you'd be better off using Drupal's AHAH functions to request an updated select element from a callback function. This way the cached form is rebuilt on the server side and you don't need to add the dreaded DANGEROUS_SKIP_CHECK. Here's a tutorial for Drupal 6:

http://randyfay.com/ahah