Using SSH over Node.js

I'm trying to run a ssh child process in node.js and control it through my program. My code:

var util   = require('util');
var spawn = require('child_process').spawn;
var ssh    = spawn('ssh', ['cloudstudios.ch']);

ssh.stdout.on('data', function (data) {
  console.log('stdout: ' + data);
});

ssh.stderr.on('data', function (data) {
  console.log('stderr: ' + data);
});

ssh.on('exit', function (code) {
  console.log('child process exited with code ' + code);
});

I can enter the password in the console, but I can't do anything after that. I get the following console ouput:

stderr: Pseudo-terminal will not be allocated because stdin is not a terminal.

root@xxxxxxxxxxxxx.xx's password:
stdout: Linux v 2.6.32-5-xen-amd64 #1 SMP Wed Jan 12 05:46:49 UTC 2011 x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.

stderr: stdin: is not a tty

Has someone an idea how I can get this to work?

Thanks!