This seems simple enough. I want to use the KeyPress event in a text box to remap keys as they are typed. Below is a bit of sample code. Of course, it doesn't work...if it did, I wouldn't be issuing this plaintive plea for help. The example below is trying to map a lower case 'a' into a lower case 'b' and a lower case 'd' into a lower case 'e'. What it actually does is do nothing when 'a' or 'd' are pressed and behaves normally otherwise. How do I do this correctly?

LPARAMETERS nKeyCode, nShiftAltCtrl
lnBefore=nKeyCode
DO CASE
     CASE lnBefore=97
          lnAfter=98
     CASE lnBefore=100
          lnAfter=101
     OTHERWISE
          lnAfter=lnBefore
ENDCASE
IF lnBefore<>lnAfter
     NODEFAULT
     nKeyCode=lnAfter
     DODEFAULT()
ENDIF