Servo Rotation Problem

hi everyone,

i'm totally newbie in programming , other electronics.
i'm trying program arduino (based on daniel's  servo code) have react photoresistor in manner.
the logic code this:

1) photoresistor captures light intensity , transform them analog signal
2) status mark set servo status 0
3) if analog signal greater 64 , status mark 0, turn servo 180 degree
4) once servo reaches 180 degree, stop.  status mark set 1
5) step 1
6) if analog signal less 64 , status mark 1, rotate servo 0 degree
7) servo reaches 0 degree, servo stop.  status mark set 0
step 1)

as guys can see, logic loop circle if statements in it.
here code:
_______________________
int servopin = 9;            //  r/c  servo connected digital pin 13
int myangle;                 // angle of servo (roughly in degrees) 0 - 180
int pulsewidth;              // function variable
int statuss = 0;
int analogvaluea= 0;    
int analogvalueb= 0;
int analogvaluec= 0;
int photocella = 0;
int photocellb = 1;
int photocellc = 2;
int ledpin = 13;
int time;
long randnumber;



void setup()
{
 beginserial(9600);
 pinmode(1, input);       // set pin a1 input
 pinmode(0, input);       // set pin a1 input
 pinmode(2, input);       // set pin a1 input
 pinmode(9, output);      // sets pin d9 output
 pinmode(13, output);     // sets pin d13 output
}

void servopulse(int servopin, int myangle)   // servo function
{                                                              // function determining our pulsewidth servo
 pulsewidth = (myangle * 6) + 320;           // determines our delay below (for standard pot)
 digitalwrite(servopin, high);                     // set servo high
 delaymicroseconds(pulsewidth);                // wait small amount (determined pulsewidth)
 digitalwrite(servopin, low);                      // set servo low
 delay(20);                                              // refresh cycle of typical servos (20 ms)
}

void loop()
{
 time = millis();          
 randnumber = random(1,4);                           // return random number 1 - 3
 serial.print(randnumber);
 serial.print(" ");
 digitalwrite(ledpin, high);                              // sets led on
 analogvaluea = analogread (photocella);
 analogvalueb = analogread (photocellb);
 analogvaluec = analogread (photocellc);
 serial.print(analogvaluea, dec);                    //prints analog value in serial message
 serial.print(" ");
 serial.print(analogvalueb, dec);                    //prints analog value in serial message
 serial.print(" ");
 serial.print(analogvaluec, dec);                    //prints analog value in serial message
 serial.print(" ");
 serial.print(randnumber);
 serial.print(" ");
 serial.print(statuss);
 serial.print(" ");
 if ((analogvaluea >= 64) , (statuss == 0)){
   for (myangle=0; myangle<=180; myangle++) {  // cycle through every angle (rotate servo 180 slowly)
     servopulse(servopin, myangle);
     statuss = 1;
     //digitalwrite(servopin, low);                 // set servo low
     //delay(20);                                   // refresh cycle of typical servos (20 ms)
   }
 }
 if ((analogvaluea <= 64) , (statuss == 1)){
   for (myangle=180; myangle>=0; myangle--) {  // cycle through every angle (rotate servo 180 slowly)
     servopulse(servopin, myangle);
     statuss = 0;
    // digitalwrite(servopin, low);                 // set servo low
    // delay(20);                                          // refresh cycle of typical servos (20 ms)
   }
 }
 delay(1000);
}
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the photoresistors , random value works fine.  the problem i'm having once servo motor rotates 180 degrees , setting status mark 1, instead of rotating 0 degree , set status mark 0, servo motor tries continue going forward (180degree +).

the reason servo tries go forward because servo jerking 180 degrees side , not jerking backward @ all.


can please have @ code , give me suggestion on how fix problem?

thank you

does have suggestion?
my problem has gotten bad worst, i've implemented daniel's simple servo code arduino , still doesn't work.
for reason, servo not go 0 degree , re-perform 180 degree turn.  note did not change on daniel's code, missing in coding part?

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