This function returns the current ADP exception state. Possible values are:
ADP was evaluated successfully
Stack overflow occurred. This might happen, for example, if there was a recursive call to ns_adp_include.
An attempt to debug failed or ns_adp_abort was called.
ns_adp_break was called
Unrecognized exception status; should not occur.
This function returns 1 if the status is "ok" and 0 otherwise. If the optional state argument is passed, it will be set with the actual state.