THANK YOU ALL !
Code:
@ DEVICE pic16F628A, INTRC_OSC, WDT_OFF, PWRT_OFF, BOD_OFF, MCLR_ON, LVP_OFF, CPD_OFF, PROTECT_OFF 

   
   Include "modedefs.bas"   ' Serial Protocol
   Define   OSC 4           ' 4MHz 
   CMCON = 7                ' Disable on-chip comparator, PORTA in digital mode
              
   '// Define port pins as inputs and outputs ...
TRISA  = %00000111
PORTB=0
TRISB = 255 ' Disconnect all resistors from the circuit


include "c:\pbp\keypad2.pbp" ' see http://www.picbasic.co.uk/forum/showthread.php?t=3250

main:
gosub keypadscan
gosub check
goto main


check:
select case key 
case 1     ; volume down
    trisb.2=0

case 2    ; track -
    trisb.3=0
   
case 3    ; volume up
    trisb.4=0
   
case 4    ; mute
    trisb.5=0
   
case 5    ; source
    trisb.6=0
   
case 6    ; track +
    trisb.7=0
   
end select
Pause 500 ' do it for 0.5 sec
TRISB = 255
Return

end 'of story !