IF..THEN syntax

[scaenix]

'Read Cds cell #1 on port b line 1
'Read Cds cell #2 on port b line 7
v1 var byte 'Variable v1 holds Cds #1 information
v2 var byte 'Variable v2 holds Cds #2 information
v3 var byte 'Variable for calculation
s1 var byte 'Variable s1 holds servomotor #1 pulse width info
s2 VAR word 'variable for random function
rv var byte 'variable rv holds the range value
s1 = 150 'initialize steering servomotor facing forward
rv = 10 'Adjust as needed for operation
ct var byte 'counter


start:
pot portb.2,255,v1
pot portb.3,255,v2

'Check bumper switch "Did I hit something?"
if porta.0 = 0 then avoid 'Hit obstacle go into avoid mode
'Is it sleepy time?
if v1 <= 230 then skp 'Is it dark enough to sleep?
if v2 > 230 then slp 'Yes

'Is it too bright to see?
skp:
if v1 >= 12 then skip2
if v2 < 12 then avoid

'Which way do I go?
skip2:
if v1 = v2 then straight
if v1 > v2 then greater
if v1 < v2 then lesser

straight:
pulsout portb.6, s1
pulsout portb.7, 157
goto start

greater:
v3 = v1 - v2
if v3 > rv then right
goto straight

lesser:
v3 = v2 - v1
if v3 > rv then left
goto straight

right:
s1 = s1 + 1
if s1 > 225 then s1 = 225
pulsout portb.6, s1
pulsout portb.7, 165
goto start
left:
s1 = s1 - 1
if s1 < 65 then s1 = 65
pulsout portb.6, s1
pulsout portb.7, 165
goto start

slp:
pulsout portb.6, s1
pulsout portb.7, 167
goto start

avoid:
random s2
s1 = s2 / 256
if s1 < 65 then s1 = 65
if s1 > 225 then s1 = 225
for ct = 1 to 125
pulsout portb.6, s1
pulsout portb.7, 177
pause 18
next ct

s1 = 150

goto start

I've quoted the code I've posted in one of the previous replies. the program is supposed to make the servomotor #1, which is connected to RB7 stop when in total darkness. I'm confused why the motor still continues on turning even if it is supposed to stop. Please anyone enlighten me on this. Thanks very much!