function lighten(anch)
{
    var newsrc = anch.src.substring(0,anch.src.length -4);
    newsrc= newsrc + "_light.jpg";
    anch.src = newsrc;
}
function darken (anch)
{
    var newsrc = anch.src.substring(0,anch.src.length -10);
    newsrc= newsrc + ".jpg";
    anch.src = newsrc;
}
function blankwin(src)
{
  var newwin = window.open(src,"picture","width=800,height=600,scrollbars=yes,toolbars=no,resizable=yes");
  newwin.focus();
}