var mPut = new Class({
    initialize: function(el) {
        el.each(function(item, index) {
            var val = item.get('value');
            item.addEvents({
                'focus': function(){
                    if(this.get('value') == val) this.set('value', '');
                },
                'blur': function(){
                    if(this.get('value') == '') this.set('value', val);
                }
            });
        });
    }
});