The docs say fn_form_pre_formName and fn_form_post_formName will only work with ajax forms. I wanted to use the built in validation but do my own submitting. Looked at the code, seems the pre-call will work no matter what, the other is only called durring ajax.
There was another one that appears to be undocumented that I found and ended up using:
fn_form_submit_post_formName.
It will only work if cm-new-window and cm-parent-window aren’t used and cm-js-post is used.
cm-js-post is another microformat that isn’t documented I don’t think
Just make sure to define the functions outside of your $(document).ready.