window.addEvent('domready', function() {
    $$('input').addEvent('focus', function(event){
        if (this.name == 'email') {
            $('field_title').set('text', 'Email:');
            $('field_explanation').set('html', 'You need to provide <b>valid email</b> address to get response!!!.');
        }
    });
    $$('textarea').addEvent('focus', function(event){
        if (this.name == 'content') {
            $('field_title').set('text', 'Content:');
            $('field_explanation').set('html', 'Please type your message in this field');
        }
    });
});