Yes. GET Request is typically for queries to the server. You would not want to send large data sets via a GET Query.
As was mentioned , you can also see very conveniently each POST param and header that is being transmitted in your POST request to the server .
If u are using FF, there is a Network Tab under tools
for Chrome its under View->Developer Tools.
This jist of what i am saying is that first check if information is going to the server via your request.
You have to keep the Network tab open in the first place and THEN submit the data.
If the data is going to the server, then as i mentioned i hope your SSL config for the web server eg : Apache is setup properly.
As far as the Server Side script is concerned, the POST Data is accessible via STDIN handle. But for ReadParse() usage you should check this link . CGI.
Here is a really nice article on beginner CGI Programming