Displaying form input instantly

[Werewolf]

I would like to know how you display directly the form input a user types in. For example like on this site, when you ask a question, your text is shown directly at the bottom. Or like on this site http://demo.tutorialzine.com/2010/01/sticky-notes-ajax-php-jquery/demo.php when you add a note, you can see on the left immediately how your sticky is going to look.I think this is done with javascript but I don't know howkind regards