function show_img(img,width,height)
{
  var a;
  var b;
  var url;
  vidWindowWidth=width;
  vidWindowHeight=height;
  a=(screen.height-vidWindowHeight)/5;
  b=(screen.width-vidWindowWidth)/2;
  features = "top=" + a + 
             ",left=" + b + 
             ",width=" + vidWindowWidth + 
             ",height=" + vidWindowHeight + 
             ",toolbar=no," + 
             "menubar=no," +
             "location=no," +
             "directories=no," +
             "scrollbars=no," +
             "resizable=no";
  url="show.php?img=" + img;
  window.open(url,'',features,true);
}
function delete_position(url, ask)
{
  if(confirm(ask))
  {
    location.href=url;
  }
  return false;
}