I have followed instructions by Andrew Embler (http://andrewembler.com/posts/javascript-jquery-and-concrete5/) to use the jQuery dialog in a self designed block under concrete 5 5.5.2.1.

This works very well in IE9 but the dialog will not open in Mozilla or Chrome. When comparing the page sources, it turns out that in the Mozilla and Chrome versions the links to jQuery.ui and ccm.dialog are missing in the Mozilla and Chrome pages and Firefox probably correctly tells me that jQuery.fn.dialog is not defined.

These links are loaded by the on_page_view() method in the block controller as specified in Andrew's article:

public function on_page_view() {
$html = Loader::helper('html');
$this->addHeaderItem($html->css('jquery.ui.css'));
$this->addHeaderItem($html->css('ccm.dialog.css'));
$this->addHeaderItem($html->javascript('jquery.ui.js'));
$this->addHeaderItem($html->javascript('ccm.dialog.js'));
}

Can anybody shed some light on what I'm missing here?