public void DrawSingleLineOfText(PdfFormField field, string text, BaseFont font, float fontSize, float llx, float lly, float urx, float ury)
{
PdfAppearance tp = PdfAppearance.CreateAppearance(writer, urx - llx, ury - lly);
PdfAppearance tp2 = (PdfAppearance)tp.Duplicate;
tp2.SetFontAndSize(font, fontSize);
tp2.ResetRGBColorFill();
field.DefaultAppearanceString = tp2;
tp.DrawTextField(0f, 0f, urx - llx, ury - lly);
tp.BeginVariableText();
tp.SaveState();
tp.Rectangle(3f, 3f, urx - llx - 6f, ury - lly - 6f);
tp.Clip();
tp.NewPath();
tp.BeginText();
tp.SetFontAndSize(font, fontSize);
tp.ResetRGBColorFill();
tp.SetTextMatrix(4, (ury - lly) / 2 - (fontSize * 0.3f));
tp.ShowText(text);
tp.EndText();
tp.RestoreState();
tp.EndVariableText();
field.SetAppearance(PdfAnnotation.APPEARANCE_NORMAL, tp);
}