DOMBuilder example

gistfile1.js

var Event = YAHOO.util.Event, DOM = YAHOO.util.Dom, DB = YAHOO.tagz.DomBuilder;
Event.onDOMReady(function() {
    Event.on('id_ok','click',function(e) {
        var s = YAHOO.lang.trim(DOM.get('id_name').value);
        if(s) {
            DOM.insertBefore(
                DB.DIV({style:{margin:'2px'}},
                    DB.SPAN(
                        {style:{color:'white','background-color':'#aa0011',padding:'2px'}},
                        'You entered: '+s)), 
                DOM.getFirstChild(document.body));
        }
    });
});