reuired fields in cms

[ohadpartuck]

Hi,
I have added two input text fields in CMS edit/publish articles.
I want those fields to be mandatory and if the users doesn't fill them,
I will popup an error msg.
which means I have to add a javascript code to
cmsFormSubmit function
(from onsubmit="return cmsFormSubmit('{vb:raw formid}', '{vb:raw editorid}');" in the vbcms_content_article_inline template)

But I can't seem to find that function anywhere!! where the heck is it?