How do I access telephone functions?

You can not access those due to the security reasons. With WTAI public library it is possible to call to a number defined in the wml deck. Also with WTAI public library it is possible to add an entry to the phonebook. So only writing is possible, not reading. WTAI non-public libraries would contain functions to also read the phonebook, but those libraries could only be used by WTA server and WTAI non-public libraries are not supported by Nokia terminals (or by any other terminals).