function hide(thing) { document.getElementById(thing).style.display = 'none'; }
function view(thing) { document.getElementById(thing).style.display = 'block'; }

function toggle(thing)
  {
    if ( document.getElementById(thing).style.display != 'block') { view(thing); }
    else if ( document.getElementById(thing).style.display != 'none') { hide(thing); }
  }