This is a snippet

function toggle(id){
    id.style.display = (id.style.display == '')? 'none' : '';
}

This code is the very basic show/hide. Two examples below on how to hide something with an id of rawr.

toggle(document.getElementById('rawr'));
toggle(get('rawr','id'));
The second uses the function that vF has built in, but in essence does exactly the same.

Enjoy.