interrupts dont seem to work at all

hi guys writing a simple program to blink a led for every 500ms using a systic timer i have observed the interrupt never occurs led stays on forever not only this but i have used many working sample programs involving interrupts but it doesnt work . Im using lpc1768(100mhz) with bootloader(factory installed) residing at 0x00000000 to 0x00002000 like is there a need to offset the vector table manually or the booloader does that by itself my application starts at 0x00002000 i have done that accordingly in keil heres the code for the systic timer

#include "LPC17xx.h"

volatile uint32_t msTicks = 0;

void SysTick_Handler(void)

{

msTicks++;//count no of ms

}

void Delay (uint32_t dlyTicks)

{
volatile uint32_t curTicks;
curTicks = msTicks;

while ((msTicks - curTicks) < dlyTicks);//stay here until delay is acheived

}

int main (void)
{ SystemInit();//core speed 100mhz

SysTick_Config(SystemCoreClock/1000);//configuring systic timer to interrupt every 1ms

LPC_SC->PCONP |= ( 1 << 15 ); // power up GPIO
LPC_GPIO1->FIODIR |= 1 << 29; // puts P1.29 into output mode.
while(1)
{

LPC_GPIO1->FIOPIN |= 1 << 29; // make P1.29 high
Delay(500);
LPC_GPIO1->FIOPIN &= ~( 1 << 29 ); // make P1.29 low
Delay(500);
}}