coding to change the state of led using push button

//}
#define PORTBIT(adr, bit)	((unsigned)(&adr)*8+(bit))

static bit LED0 @ PORTBIT(PORTC, 0) ;
static bit LED1 @ PORTBIT(PORTC, 1) ;
static bit LED2 @ PORTBIT(PORTC, 2) ;
static bit LED3 @ PORTBIT(PORTC, 3) ;


unsigned int pattern = 1; // Initialize pattern equal to zero

void main()
{
ANSEL = 0; // Intialize A/D ports off
PORTC = 0x00; //Clear PortC port

TRISC = 0x00; //All PortC I/O outputs
TRISA = 0xFF; //All PortA I/O inputs

while(1==1) //loop forever
{
//check if button is pressed

if(RA3==0)
{
while (!RA3); // Hold here until switch is released
_delay_ms(10); // Delay 10 milliseconds and check again
while (!RA3); // For simple debounce of switch

pattern=pattern+1;
if(pattern>3) {pattern=1;}
}
   LED0 = 1;
delay_ms(500);

LED0 = 0;
LED1 = 1;
delay_ms(500);

LED1 = 0;
LED2 = 1;
delay_ms(500);

LED2 = 0;
LED3 = 1;
delay_ms(500);

LED3 = 0;
LED2 = 1;
delay_ms(10);

LED2 = 0;
LED1 = 1;
delay_ms(10);

LED1 = 0;
LED0 = 1;
delay_ms(10);

PORTC = 0b00000000;

}

if(pattern==2)
{
//	LED1=1;


PORTC = 0b10101010;
delay_ms(10);

PORTC = 0b01010101;
delay_ms(20);

}


if(pattern==3)
{
//forward
LED0 = 1;
delay_ms(300);

LED0 = 0;
LED1 = 1;
delay_ms(300);

LED1 = 0;
LED2 = 1;
delay_ms(300);

LED2 = 0;
LED3 = 1;
delay_ms(300);

LED3 = 0;
LED2 = 1;
delay_ms(300);

LED2 = 0;
LED1 = 1;
delay_ms(300);

LED1 = 0;
LED0 = 1;
delay_ms(300);
PORTC = 0b00000000;

}