code: public boolean setFieldAsString(String field, String value) {
          return setField(field, new PdfString(value, PdfObject.TEXT_UNICODE));
      }
docs: Sets the field value as a string.
  @param field the fully qualified field name
  @param value the value
  @return <CODE>true</CODE> if the value was inserted,
  <CODE>false</CODE> if the name is incompatible with
  an existing field