Usage of markText with className option

Hi. I’m trying to use markText with the className option and I have some troubles. I’ve defined a CSS in a style tag like that:

.disabled { background-color: #FF0000; }

and I call the function in a script tag as follow:

window.editor.markText( {line:6,ch:4}, {line:6,ch:23}, {readOnly:true}, {className: "disabled"});

The lines from 4 to 23 become correctly readOnly, but the background doesn’t change and I can’t understand why. Could it be some conflicts with something else?

Thanks in advice.

******* EDIT *******
I’ve solved like this:

window.editor.markText( {line:6,ch:4}, {line:6,ch:23}, {readOnly:true, className: "disabled"});

Stupid mistake, my apologize.