The old_function statement allows you to
declare a function using a syntax identical to PHP/FI2 (except you
must replace 'function' with 'old_function'.
This is a deprecated feature, and should only be used by the
PHP/FI2->PHP 3 convertor.
Functions declared as old_function cannot be
called from PHP's internal code. Among other things, this means
you can't use them in functions such as
usort(), array_walk(), and
register_shutdown_function(). You can get
around this limitation by writing a wrapper function (in normal
PHP 3 form) to call the old_function.