problem con HTTP_POST_VARS

Hi, I am new in this php world and I have been having some problems, my program gives me this error "Warning: Variable passed to each() is not an array or object in /usr/local/etc/httpd/htdocs/fondef/seguimiento/cgi-bin/act_situacion.php3 on line 8" I call this function like this: <form name="myform" method="post" action="act_situacion.php3<?php echo $stringparam; ?>" onSubmit="return confirmasit('<?php echo $agente; ?>',boton)"> The line num. 8 of act_situacion has: while (list($key,$val)=each($HTTP_POST_VARS)) I have the track_vars enabled in the configuration. I have Apache with PHP3 on HP-UX 10.20 IDS2000. They told me too that PHP4.0 does not support the track_vars . Is this true? Also, somebody told me that with https the array HTTP_POST_VARS is sent empty. Is this true too? Thanks a lot, Elena Hernández O. Jefe de Proyecto 56-2-3654533 Depatmento de Computación CONICYT CHILE