Mess with display files...

This is a multi-part message in MIME format.
--
[ Picked text/plain from multipart/alternative ]
Can someone find some 10 minutes to explain me, what am I doing wrong?
I have a trivial display file named Y20DMD5:

A                                      DSPSIZ(24 80 *DS3)
A                                      CF03(03 'EXIT')
A          R CHRG
A                                  3  2'Customer . . .'
A            CUSCPNC        6A  B  3 17COLOR(WHT)
A  61                                  ERRMSG('Error2')
A            CUSNAME       35A  O  3 28
A                                 23  2'F3=Exit'
A                                      COLOR(TRQ)

Then I have a trivial C program :

#include <stdio.h>
#include <stdlib.h>
#include <recio.h>
#include <string.h>

#pragma mapinc("hdrf", "*LIBL/Y20DMD5(CHRG)", "both", "_P", "D1", "D1")
#include "hdrf"
#define INPUT_T  D1_CHRG_i_t
#define OUTPUT_T D1_CHRG_o_t

#define IND_ON '1'
#define IND_OFF '0'

int main(void)
{
  _RFILE *fp ;
  _RIOFB_T *rfb ;
  INPUT_T ScreenIn ;
  OUTPUT_T ScreenOut ;

  if ((fp = _Ropen("*LIBL/Y20DMD5", "rr+") ) == NULL)
    return(0) ;

  _Rformat (fp, "CHRG") ;
  ScreenOut.IN61 = IND_OFF ;
  memset(ScreenOut.CUSCPNC, ' ', 6) ;
  memset(ScreenOut.CUSNAME, ' ', 35) ;

  while (1)
  {
    rfb = _Rwrite(fp, &ScreenOut, sizeof(OUTPUT_T)) ;
    rfb = _Rreadn(fp, &ScreenIn, sizeof(INPUT_T), __DFT) ;
    ScreenOut.IN61 = IND_OFF ;
    if ((ScreenIn.IN03 == IND_ON))
    {
      _Rclose(fp) ;
      return(0) ;
    }
    memset(ScreenOut.CUSNAME, 'A', 35) ;
    ScreenOut.IN61 = IND_ON ;
    memcpy(ScreenOut.CUSCPNC, ScreenIn.CUSCPNC, 6) ;
  }
}

It shows a customer prompt and when I enter customer it shows "Error1" on an 
error bar, but for some strange reason does not show, that the CUSNAME field 
has new value!
At the same time, if I remove the row, setting IN61 to ON, everything is OK.
What I want, is that it shows changed CUSNAME field AND ALSO an error text.
Any advise will be highly appreciated!

Thanks in advance,

Jevgeni Astanovski.

--