LPC2138 don't go to interrupt subroutine function

#include "lpc213x.h"  // Header file for Phillips LPC2138 controller
void init()
{
        PLLCFG=0x24;     // MSEL = 4,PSEL = 2
        PLLFEED=0xAA;    // Feed process
        PLLFEED=0x55;

        PLLCON=0x1;
        PLLFEED=0xAA;   // Feed process
        PLLFEED=0x55;

        while(!(PLLSTAT & 0x400)) ;   // Wait until PLL Locked

        PLLCON=0x3;      // Connect the PLL as the clock source
        PLLFEED=0xAA;    // Feed process
        PLLFEED=0x55;

        MAMCR=0x2;        // Enabling MAM and setting number of clocks used for Flash memory fetch (4 cclks in this case)
        MAMTIM=0x4;

        VPBDIV=0x02;     // PCLK at 30 MHz

}

void isr_int2(void) __irq
{
    FIO0PIN ^= (1<<21); // Toggle LED at P0.21
    EXTINT |= 0x4;      // Clear interrupt flag EINT2
    VICVectAddr = 0;    // Acknowledge Interrupt
}

int main()
{
        init();         // Initialize the system
        SCS = 0x03;     // select the "fast" version of the I/O ports
        FIO0DIR |= (3<<21); // Config. output P0.21, p0.22 connect LED
    FIO0SET |= (3<<21); // OFF LED
    EXTMODE |= 0x4;    // EINT2 Edge sensitive detection(Falling edge in this program)
    PINSEL0 = 0xC000;   // Enable EINT2 at P0.7
    VICVectAddr0 = (unsigned)isr_int2; // Register Interrupt service routine name
    VICVectCntl0 = 0x20 | 16; // EINT2 Interrupt
    VICIntEnable |= 1 << 16;   // Enable EINT2 Interrupt
while(1){
    FIO0SET |= (1<<22); // OFF LED
    delay_ms(500);  // Delay 500 ms
    FIO0CLR |= (1<<22); // On LED
    delay_ms(500);  // Delay 500 ms
}   // Infinite loop
}