HTML 5 brings many new features to the browser including a lot of enhancements to the way forms are created and handled. One of my favourite features is the introduction of the placeholder attribute, this allows the display of some text in a text input field or text area until the element is brought into focus. This allows the addition of small tips or related prompts to give the user a better understanding of what is required as input.
You should now be able to add placeholder attributes to the text form elements throughout your site and have them be backward compatible with incompatible browsers eg
<input type="text" name="user_name" placeholder="enter username">