Using https module for http requests

I am now using the https module to send some https POST requests.

A new requirement came up: the server's SSL support may be switched on or off. So I must use either https or http accordingly.

How do I send http requests using the https module? (the opposite would be helpful too)

According to the docs for function https.request(options[, callback]),

options.protocol Defaults to https:

---

I tried changing this to http:, for example,

 var options = {
        protocol: "http:",
        ...
    };
 https.request(options, function (res) { ... });

but got error Error: Protocol "http:" not supported. Expected "https:"

via sam