function ShowPicture()
{
  var picHolder = document.getElementById('BigPictureFrame');
  picHolder.originalHTML = picHolder.innerHTML;
  picHolder.innerHTML = '';
  
  var pic = document.createElement('img');
  pic.id = 'TheBigPicture';
  pic.src = this.src.replace("thm_", "ovr_");
  pic.alt = this.alt;
  picHolder.appendChild(pic);
}


function HidePicture()
{
  var pic = document.getElementById('TheBigPicture');
  picHolder = pic.parentNode;
  picHolder.removeChild(pic);
  picHolder.innerHTML = picHolder.originalHTML;
}


function Page_Load()
{
  var tblThumbnails = document.getElementById('Thumbnails');
  var images = tblThumbnails.getElementsByTagName('img');
  for( var x = 0; x < images.length; x++ )
  {
    var img = images[x];
    img.onmouseover = ShowPicture;
    img.onmouseout = HidePicture;
  }
}

window.onload = Page_Load;