Talk about writing modules and plugins for CMS Made Simple, or about specific core functionality. This board is for PHP programmers that are contributing to CMSMS not for site developers
On your PHP page that calls this template, do a print_r on $fb_form_validation_errors. Then submit the form again with errors and print_r will display all the keys and values of the validation_errors.
It looks like the array doesn't contain the information you want. It only contains the message. You have two choices now
1) Start hacking the formbuilder module so that it will pass the field labels separately. NOTE: you will need to have a good understanding of PHP to do this.
2) On the action.default.php parse out the field labels in the values of the $res[1] array. e.g. parse "Name" from 'Please enter a value for "Name" '
p.s. are you only doing this so that you can have the error message display in another language? if so, formbuilder comes with many build in languages.
If you look at the page/tab, when editing the form, that has the form, generate form or some such wording it has all the fields the form will generate...