public PdfFormField AddSignature(String name, float llx, float lly, float urx, float ury)
{
PdfFormField signature = PdfFormField.CreateSignature(writer);
SetSignatureParams(signature, name, llx, lly, urx, ury);
DrawSignatureAppearences(signature, llx, lly, urx, ury);
AddFormField(signature);
return(signature);
}