Since IPS never tells you anything , you have to use display techniques to get the information it passes.
So for information purposes add tis to the code and it will create a file with the input data. Something like this
$file = fopen("/cache/IP_Nexus.cgi","a");
fputs($file,"n Member n".print_r($member,true)."n");
fputs($file,"n Package n".print_r($package,true)."n");
fputs($file,"n Invoice n".print_r($invoice,true)."n");
fclose($file);
This assumes the forum is in the root (public_html) folder. If in a folder called forum then this "/cache/IP_Nexus.cgi" should be "/forum/cache/IP_Nexus.cgi"