function imageshow(obj,image)
{
  setBackgroundImage(obj,"url(" + image + ")");
}

function imagehide(obj)
{
  setBackgroundImage(obj,"none");
}

function setBackgroundImage(obj,image)
{
  var style = '';
  if (document.getElementById)
  {
    style = document.getElementById(obj).style;
  }
  else if (document.all)
  {
    style = document.all[obj].style;
  }
  else if (document.layers)
  {
    style = document.layers[obj].style;
  }
  if (style != '')
  {
    style.backgroundImage = image; 
  }
}