Interrupt on Change Problem

#include <htc.h>

/*CONFIGURATION*/
__CONFIG(FOSC_XT & WDTE_OFF & CP_OFF & PWRTE_OFF);

/*PIN ASSIGNMENTS*/
#define BUTTON 4
#define bLED   0
/*GLOBAL VARIABLES*/
unsigned char sPORTB;           //Create Shadow copy of PORTB

/*FUNCTION PROTOTYPING*/
void init();
void toggle();

void main()
{
    init();                     //CALL Initialize Function
    //MAIN LOOP
    for(;;)
    {
        PORTB = sPORTB;         //Update PORTB
    }
}

/*INITIALIZE Function*/
void init()
{
    /*INITIALIZATIONS*/
    TRISB = ~(1<<bLED);         //SET RB0 as OUTPUT
    PORTB = 0x00;         //SET PORTB to 0
    sPORTB = 0x00;        //SET Shadow of PORTB to 0
    
    /*CONFIGURE INTERRPUT*/
    RBIE = 1;                   //ENABLE PORTB Interrupt-on-change
    ei();                       //ENABLE Global Interrupt
}

/*INTERRUPT SERVICE ROUTINE*/
void interrupt isr(void)
{
    RBIF = 0;                   //CLEAR interrupt FLAG
    if(!(PORTB & 1<<BUTTON))    //If BUTTON is Down
    {
        sPORTB ^= (1<<bLED);
    }
}

if(RBIF == 1)
  {
  if(!(PORTB & (1 << BUTTON)))        // Use more brckets!
    {
    sPORTB ^= (1<<bLED);
    RBIF = 0;
    }
  }