title: Not able to write multiple annotation images in itextsharp
body: <p>Here i am trying to add to images as overlay on text.so i used pushbutton and annotations. but i can write only one image.not able to write second image onwards.Please help me</p>
  
  <pre><code>PdfReader reader1 = new PdfReader(Path);
  FileStream fs = new FileStream(OutLocation, FileMode.Create,    FileAccess.Write,FileShare.None);
  PdfStamper stamper = new PdfStamper(reader1, fs);
  PushbuttonField fld = new PushbuttonField(stamper.Writer,
      new iTextSharp.text.Rectangle(315, 400, 210, 250), "Test ");
  fld.Layout = PushbuttonField.LAYOUT_ICON_ONLY;
  string Img = path + "RedSlash.png";
  iTextSharp.text.Image jpeg = iTextSharp.text.Image.GetInstance(Img);
  jpeg.ScaleToFit(100, 200);
  fld.Image = jpeg;
  stamper.AddAnnotation(fld.Field, 1);
  fld1 = new PushbuttonField(stamper.Writer,
      new  iTextSharp.text.Rectangle(500, 500, 210, 250), "Test ");
  fld1.Layout = PushbuttonField.LAYOUT_ICON_ONLY;        
  iTextSharp.text.Image jpeg1 = iTextSharp.text.Image.GetInstance(Img);
  jpeg1.ScaleToFit(100, 200);
  fld1.Image = jpeg1;
  stamper.AddAnnotation(fld1.Field, 1);
  </code></pre>