Kouakou,

If what you are trying to accomplish is to prevent backspace from taking you out of a textbox into the previous control (one of the most truly annoying things in VFP) is to put this code into your lowest level textbox subclass:

LPARAMETERS nKeyCode, nShiftAltCtrl

if ( ( m.nKeyCode = 127 ) and ( this.SelStart = 0 ) )
   * prevent backspace from leaving this field
   nodefault
endif

>how to deactivate the backspace key ?