Opening a page after login doesn't work - phantomjs

Question

Using PhantomJs & CasperJs, I would like to :
Get the login page of a website
Fill the form and send it
Once i'm connected, get the content of an other page.
I'm stuck at step 3.
I absolutely do not understand how to get another page after the first one.
I read the documentation, many forums, etc ...
Here's my code :
(I did replace login/password and links).
var casper = require('casper').create({
clientScripts: ["lib/jquery-2.1.1.min.js"]
});
casper.start("https://my_website/login");
casper.waitForSelector('#username', function() {
this.fill('form#fm1', {
'username': "...",
'password': '...'
}, true);
});
casper.then(function() {
//this.echo('Title : ' + this.getTitle());
//this.echo('Title : ' + this.page.content);
// if the page contains the word "Connected",
// the connexion is successful
if (this.page.content.indexOf("Connected") > -1) {
console.log("Connected");
}
});
casper.thenOpen('https://my_website.com/myplanning.jsp', function(response) {
// HERE'S THE PROBLEM !!!!!!!!
console.log(this.getPageContent());
});
casper.waitForSelector('#inner0', function() {
// HERE'S AN OTHER PROBLEM !!!!!!!!
console.log('Great !');
});
casper.run(function() {
this.exit();
});
How can I get the content of "https://my_website.com/myplanning.jsp"?