function setBGImage(thing, image) {
    document.getElementById(thing).style.backgroundImage = 'url(' + image + ')';
    document.getElementById(thing).style.backgroundRepeat = 'no-repeat';
    document.getElementById(thing).style.backgroundPosition = 'center center';
}
function changeBGColor(thing) {
  if (document.getElementById) {
    document.getElementById(thing).style.backgroundImage = 'url("")';
    document.getElementById(thing + '_body').style.visibility = 'visible';
    document.getElementById(thing).style.background = '#ffffff';
  }
}
function changeBGImage(thing) {
  if (document.getElementById) {
    document.getElementById(thing + '_body').style.visibility = 'hidden';
    setBGImage(thing, 'images/logo_' + thing + '.png');
  }
}