CC430f5137 ADC12 trigger by timer

Hi ,

I need help.

I am working on ADC using cc430f5137. 

#include <msp430.h>
//#include <studio.h>

#define Num_of_Results 8
unsigned int ADC_value;

void ConfigureAdc(void)
{
P2SEL |= BIT2; // Enable A/D channel inputs
ADC12CTL0 = ADC12ON+ADC12MSC+ADC12SHT0_8; // Turn on ADC12_A, extend sampling time
// to avoid overflow of results
ADC12CTL1 = ADC12SHP+ADC12CONSEQ_3; // Use sampling timer, repeated sequence
ADC12MCTL2 = ADC12INCH_2; // ref+=AVcc, channel = A2
ADC12IE = 0x08; // Enable ADC12IFG.3
ADC12CTL0 |= ADC12ENC; // Enable conversions
ADC12CTL0 |= ADC12SC; // Start conversion - software trigger
}

int main(void)
{
WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer

ConfigureAdc();
__bis_SR_register(LPM0_bits + GIE); // Enter LPM0, Enable interrupts
__no_operation(); // For debugger
}

#pragma vector=ADC12_VECTOR
__interrupt void ADC12_ISR (void)

{
ADC_value = ADC12MEM2;

}

with this code I am getting correct ADC value but I want to trigger ADC by timer.

I don't understand how to setup timer to trigger ADC.

Please give me some suggestion and anybody have example code please share with me. 

Nahid