ftp upload

[Gilles Durys]

I'm trying to upload a file to a ftp server with the following code
(modified from mozblog).

function uploadFile()
{
        var ioService = Components.classes["@mozilla.org/network/io-service;1"]
                .getService(Components.interfaces.nsIIOService);
        var url = Components.classes["@mozilla.org/network/standard-url;1"];
        fileurl = url.createInstance(Components.interfaces.nsIURL);
        fileurl.spec = "file:///home/sco/polom.html";

        var srcChannel = ioService.newChannelFromURI(fileurl);
        var remoteUrl = url.createInstance(Components.interfaces.nsIURL);
        remoteUrl.spec = "ftp://sco:[EMAIL PROTECTED]/downloads/polom.txt";;
        var ftpChannel = ioService.newChannelFromURI(remoteUrl)
                .QueryInterface(Components.interfaces.nsIUploadChannel);
        
        var bufferedStream =
                Components.classes["@mozilla.org/network/buffered-input-stream;1"]
                .createInstance(Components.interfaces.nsIBufferedInputStream);
        bufferedStream.init(srcChannel.open(), srcChannel.contentLength);
        ftpChannel.setUploadStream(bufferedStream,null,-1);
        ftpChannel.asyncOpen(myListener(), null);
}

Calling that function gives me the following error:

uncaught exception: [Exception... "Component returned failure code: 0x8000ffff 
(NS_ERROR_UNEXPECTED) [nsIChannel.open]"  nsresult: "0x8000ffff (NS_ERROR_UNEXPECTED)" 
 location: "JS frame :: uploadPic.js :: uploadFile :: line 15"  data: no]


I'm a little lost there, so any help/hint/lead is welcome.

-- 
Gilles