POP-X2 Simple Line Tracking Turn Lefr when Cross

#include <popx2.h>  // POP-X2 Board
word L,R,C=500,j=0;
void setup() {
  OK();
  setTextSize(3);
}
void loop() {
  L=analog(0);R=analog(1);
  if(L>C&&R>C){fd2(43,45);}
  else if(L<C&&R>C){sl(50);}
  else if(L>C&&R<C){sr(50);}
  else if(L<C&&R<C){
    fd2(43,45);sound(600,200);//delay(400);
    while(analog(0)>C){sl(40);}
    while(analog(0)<C){sl(40);}
  }
  if(analog(2)>250){
    ao();
      setTextColor(color[1]);glcd(1,1,"S");
      setTextColor(color[2]);glcd(1,2,"T");
      setTextColor(color[3]);glcd(1,3,"O");
      setTextColor(color[5]);glcd(1,4,"P");
      setTextColor(color[6]);glcd(1,5,"!");
    while(analog(2)>250);
      setTextColor(color[1]);glcd(1,1,"R");
      setTextColor(color[2]);glcd(1,2,"U");
      setTextColor(color[3]);glcd(1,3,"N");
      setTextColor(color[5]);glcd(1,4," ");
      setTextColor(color[6]);glcd(1,5,"!");
      j++;
      setTextColor(color[7]);glcd(2,1,"%d ",j);
      delay(500);
  }
}