public PdfFormField AddMap(string name, string value, string url, PdfContentByte appearance, float llx, float lly, float urx, float ury)
{
PdfAction action = PdfAction.CreateSubmitForm(url, null, PdfAction.SUBMIT_HTML_FORMAT | PdfAction.SUBMIT_COORDINATES);
PdfFormField button = new PdfFormField(writer, llx, lly, urx, ury, action);
SetButtonParams(button, PdfFormField.FF_PUSHBUTTON, name, null);
PdfAppearance pa = PdfAppearance.CreateAppearance(writer, urx - llx, ury - lly);
pa.Add(appearance);
button.SetAppearance(PdfAnnotation.APPEARANCE_NORMAL, pa);
AddFormField(button);
return button;
}