Lpc2000

I have a problem in firing the inteerupt in ISR.I have posted my 
source code here for your ref.Iam checking for a flag, in main()- 
while()loop, which is never enabled in TIMER ISR.But when i used 
polling mode its working fine. So I think I definately missing some 
things some where. I have used this timer ISR to trigger for every 
10seconds.
Environment: Eclipse/GNUARM/LPC2214..
I didnt do any thing related to this ISR in any of the startup file 
and linker script..Please help me on this.

/******************************

main()
{
InitVIC();
	while(1)
	{
		if(Timer_Flag==1)
		{
			LEDON;		
		}
	}

}

void InitVIC()
{
  VICProtection = 0;  // Setup interrupt controller.


  VICIntEnClear = 0xffffffbf;  // Disable all interrupts but the one 
used for the ROM monitor

  VICDefVectAddr = (unsigned int)&DefDummyInterrupt;

  T0TCR = 2; // Disable timer 0. and rese
  T0PC = 0; // Prescaler is set to no division.
  T0MR0 = 0xE666;	//PCLKFREQ/1000; // Count up to this value. 
Generate 1000 Hz interrupt.
  T0MCR = 3; // Reset and interrupt on MR0 (match register 0).
  T0CCR = 0; // Capture is disabled.
  T0EMR = 0; // No external match output.

  T0TCR = 1; // Enable timer 0.

  VICIntSelect &= ~(0x10);  // IRQ on timer 0 line.
  VICVectAddr1 = (unsigned int)TimerInterrupt;
  VICVectCntl1 = 0x20 | 0x04; // Enable vector interrupt for timer 0.
  VICIntEnable = 0x10;    // Enable timer 0 interrupt.
}

// Timer interrupt handler
static void TimerInterrupt()
{
  (*timer_function)(); // Call timer callback function.
  
  Timer_Count++;
  Timer_Flag=0;	

  if(Timer_Count>10000)
  {Timer_Count=0;Timer_Flag=1;}

  T0IR = 0xff; // Clear timer 0 interrupt line.
}

//Dummy interrupt handler, called as default in irqHandler() if no 
other vectored interrupt is called.
static void DefDummyInterrupt()
{}
**/