#include <P18F458.h>
#define MYBIT PORTBbits.RB5  
void main(void)
  {
    unsigned int z;
    TRISBbits.TRISB5 = 0;		
    for(z=0;z<50000;z++)
      {
        MYBIT = 1;
        MYBIT = 0;
      }
    while(1);			
  }