How to login to a website, upload a file and retrieve the link of the uploaded link?

[sadnem(gmx)]

Hi, searching on the internet I found this script 
(http://pastebin.com/WEA1eqAA) that uploads files to megaupload then 
retrieve´s the uploaded link and finally saves them on a text file, I 
really liked that about curl (Didn´t know much about it before) and now 
I was wondering how could i make this kind of script to the 4 sites I 
use (Netload,hotfile,x7.to and ugotfile) can anyone instrusct me a 
little bit how to do it? (And yes, I´ve read 
http://curl.haxx.se/docs/manual.html, 
http://curl.haxx.se/docs/httpscripting.html and curl --help and I´m 
still a curl newbie)
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