need help quick!!!! basic stamp......

here is a copy of the program i am running........ i have constructed a bot that i am hoping to run autonomously. this is basically an automated refrigerator with obstacle avoidance. with the basic program that i am running right now a universal remote initiates the movement of the bot and it then runs through the obs. avoidance. as it runs through the obs. avoidance i would like to beable to stop the bot by pressing another button, but with the way i have it written it wont exit out of the loop command....... i have tried many different things to try and execute this simple stop command but nothing seems to work.. any suggestions


' {$STAMP BS2}
' {$PBASIC 2.5}

DEBUG "program running"

'------------[variables]-----------------------------------------------

irdetectleft VAR BIT
irdetectright VAR BIT
irdetectcenter VAR BIT
BUTTON_CODE VAR BYTE 'Infrated Button Code
DEVICE_CODE VAR BYTE 'Infrared Device Code
'------------[main routine]--------------------------------------------
'***************************
'* MAIN PROGRAM *
'***************************

MAIN:
GOSUB COMMAND_030 'Send the Remote control Command to Infrated Control Freak

GOTO MAIN

COMMAND_030:
SEROUT 14, 16468, [30]
poop:
SERIN 15, 16468,1000,main, [device_code, button_code]
DEBUG "button code =", DEC Button_Code," Device Code =",DEC Device_code," ", CR
DEBUG " ",CR
DEBUG "____________________________",CR
DEBUG HOME
IF Button_code = 21 AND Device_code = 1 THEN obstacle_avoidance
IF BUTTON_code = 101 AND device_code = 1 THEN STOP_bot
GOTO poop



'----------[subroutines]----------------------------------------------



obstacle_avoidance:
DO
FREQOUT 8, 1, 38500
irdetectleft = IN9

FREQOUT 2,1, 38500
irdetectright = IN0

FREQOUT 3,1, 38500
irdetectcenter = IN4

IF (irdetectcenter = 0) THEN
GOSUB back_up
ELSEIF (irdetectleft = 0) THEN
GOSUB turn_right
ELSEIF (irdetectright = 0) THEN
GOSUB turn_left
ELSE
GOSUB forward_pulse
ENDIF
LOOP

forward_pulse:
PAUSE 100
SEROUT 16, 8276, ["!A1E", CR]
SEROUT 16, 8276, ["!b1E", CR]
RETURN

turn_left:
PAUSE 20
SEROUT 16, 8276, ["!A14", CR]
SEROUT 16, 8276, ["!b14", CR]
RETURN

turn_right:
PAUSE 20
SEROUT 16, 8276, ["!A1E", CR]
SEROUT 16, 8276, ["!b1E", CR]
RETURN

back_up:
PAUSE 20
SEROUT 16, 8276, ["!a1E", CR]
SEROUT 16, 8276, ["!B1E", CR]
RETURN

STOP_bot:
PAUSE 20
SEROUT 16, 8276, ["!A00", CR]
SEROUT 16, 8276, ["!B00", CR]