Validation: form_error and set_value

[eluser]CodeIgniterNewbie[/eluser]
I need to assign all the values of form_error and set_value to Smarty variables. Here are my problems:

1. I can't seem to access the values from form_error and set_value (I'm sure that the field names I'm passing are correct).

2. I need to set these variables WITHOUT knowing what the actual field names are. Is there an associative array I can loop though to get the field name and corresponding value or error?

Thanks.