ActionScript 3.0 :: How To Make Post Request With Tumblr API

So I'm trying to code an AIR widget for Tumblr. Before I actually start working on the widget, I wanted to play around with AS3 and the Tumblr API to do simple things, like reading and writing posts, editing posts etc. I got reading posts working, but when it comes to creating posts I run into an unknown brickwall. Here's the instructions from Tumblr's API doc on making a POST request:

The Write API is a very simple HTTP interface. To create a post, send a POST request to [URL] with the following parameters:
Email - Your account's email address.
password - Your account's password.
type - The post type.

These are the valid values for the type parameter, with the associated content parameters that each type supports:
Regular - Requires at least one:
Title
Body (HTML allowed)
[URL]

And here's my AS3 code:
import flash.net.*
gogo.buttonMode = true; // gogo is the instance name of a MC on the stage
gogo.addEventListener(MouseEvent.MOUSE_DOWN, go);
function go(e:MouseEvent):void{
var variables:URLVariables = new URLVariables();
[Code] .....
And for the life of me, no matter how simple I make this code, I cannot get it to work.