function viewphoto(string,w,h)
 {
  w = w + 20;
  h = h + 30;
  var t=(screen.height-h)/2;
  var l=(screen.width-w)/2;
  
  param='width='+w+',height='+h+',top='+t+',left='+l+'';
  foto=window.open(string,'foto',param); return true;
 }