#include <p18f4580.h>
#define mybit PORTBbits.RB4
void main(void)
  { 
    TRISBbits.TRISB4=0;
    T2CON=0x7B;		
    TMR2=0x00;				
	while(1)
      {
    	PR2=255;				
    	T2CONbits.TMR2ON=1;		
    	while(PIR1bits.TMR2IF==0);	
    	mybit=~mybit;			
	T2CONbits.TMR2ON=0;		
     PIR1bits.TMR2IF=0;			
	}
  }