function OpenPic(img)
{
  myImage= new Image();
  myImage.src=(img);
  Controlla(img);
}

function Controlla(img)
{
  if ((myImage.width != 0) && (myImage.height != 0))
  {
    viewImage(img);
  }
  else{
    funzione="Controlla('"+img+"')";
    intInterval = setTimeout(funzione, 10);
  }
}

function viewImage(img)
{
  lngWidth = myImage.width + 20;
  lngheight = myImage.height+ 20;
  mystring = "width=" + lngWidth + ", height=" + lngheight;
  finestra = window.open(img,'_blank',mystring);
}