Subfile question

HI
 
In the sample below, I am displaying a subfile that are all OUTPUT only except for 2 fields where you can put an 'X" and it will then display more info in a new screen. When I come back from that screen, I want any X's that were entered prior to become blanks. I am using the READC to check for the X.. It will of course disregard the prior X and only look at a new X but I am thinking it looks bad and wanted to clear but when I do a SFLCLR and SFLBLD again I get a blank screen. I was wondering how the clear can be accomplished that is, the entire subfile should be checked. is this an update function perhaps?
 
I PO#         ORD                                         INV       ACT     EDI
              DATE  STAT ORD#     ACCT  STR#      INV#    DATE      SHPDT     
X 11          040601 090 000008  99967            99994  040603    000000    
  11          021202 060  000013  99932            99999  021204    021204    
  11          021205 060 000055   99932            999995  021209    021209    
  11          070516 090 0058308  99950  0001   999994  070518    000000