Problem in calling the function in ISR

#include "adc.h"
#include "lcd.h"
#include "lcd1.h"
#include "systemInit.h"
#include "delay.h"
#include <stdio.h>
#include "string.h"
//#include "uart.h"
#include "config.h"
#include "stdlib.h"

#define BUZZER (1 << 25)
#define BUZZER_DIR IO1DIR
#define BUZZER_SET IO1SET
#define BUZZER_CLR IO1CLR

#define TIMER_TICK_1_MS (59999) /* VPB at 60 MHz clock */

static unsigned int ms_count;

void delay2(int count);
void TimerInit(void);

unsigned char buf[16] = {0};
int adcValue;//x
int adcValue1;//y
int adcValue2;//z
int adcValue3;//for X difference
int adcValue4;//for Y difference
int adcValue5;//for Z difference

int delta_x;
int delta_y;
int delta_z;
int thx_x = 10;
int thx_y = 10;
int thx_z = 10;

int a,b;
float temp;
unsigned int sensor_detect();


void delayMS(unsigned int milliseconds)
{
 /*Assuming that PLL0 has been setup with CCLK = 60Mhz and PCLK also = 60Mhz.*/
 
 T0CTCR = 0;
 T0PR = 60000; //60000 clock cycles = 1 mS @ 60Mhz
 
 T0TCR = 0x02; //Reset Timer
 T0TC = 0;
 T0TCR = 0x01; //Enable timer
 
 while(T0TC < milliseconds); //wait until timer counter reaches the desired delay
 
 T0TCR = 0x00; //Disable timer
}

void Timer_ISR(void) __irq
{
ms_count++;
 
///* Count increments for every 1MSec */
 
if(ms_count == 10) 
{
sensor_detect();
}
ms_count = 0;
 
T1IR = 0x01;
VICVectAddr = 0x00; 
}


void TimerInit(void)
{
 T1TCR = 0x00; /* ensure timer 1 is off */
 /* set timer counter and prescale counter */
 T1TC = 0x0;
 T1PC = 0x0;
 
 /* set prescale and match values to give 1 ms "tick" */
 T1PR = 0x0;
 T1MR0 = TIMER_TICK_1_MS;
 
 /* set control to interrupt on MR0 match, and reset to 0 (i.e. "tick") */
 T1MCR = 0x3;
 
 /* vector TIMER 1 as mid-level priority and enabled */
 VICVectCntl11 = 0x25;
 
 /* vector TIMER 1 interrupt address */
 VICVectAddr11 = (unsigned int) Timer_ISR;
 
 /* enable TIMER 1 in VIC */
 VICIntEnable = 0x0020;
 
 /* go start timer 1... */
 T1TCR = 0x1;
}
 

int main() 
{
 
  ADC_Init();
  init_lcd();
 
  TimerInit();     //Timer initialisation
 
  lcd_clear();        // clear display
while(1)
{
 
 sprintf((char *)buf, "a:%d ",a);//need to print the sensor values 0 and 1 here
 lcd_putstring(0, (char *)buf);
 
}
}
 
unsigned int sensor_detect()
{
 
    ADC_Init(); 
        adcValue =  ADC_GetAdcValue(AD0_1);//x // Read the ADC value of channel zero where the temperature sensor(LM35) is connected
        adcValue1 = ADC_GetAdcValue(AD0_2);//y
    adcValue2 = ADC_GetAdcValue(AD0_4);//z 
    
 
    sprintf((char *)buf," X=%4d",adcValue-804);
//      lcd_putstring(0, (char *)buf);

    sprintf((char *)buf,"   Y=%4d",adcValue1-813);
//      lcd_putstring(0, (char *)buf);

    sprintf((char *)buf,"       Z=%4d",adcValue2-601);
//      lcd_putstring(1, (char *)buf);
    delayMS(50);

    adcValue3 = ADC_GetAdcValue(AD0_1); //X AXIS
    delta_x = adcValue - adcValue3;
    if (delta_x > thx_x)
    {
     BUZZER_DIR |= BUZZER;
     BUZZER_SET |= BUZZER;
    a=1;//need to print this value in main function
      sprintf((char *)buf, "a:%d ",a);
     lcd_putstring(0, (char *)buf);
    }
 ////////////////////////////////////// 
    adcValue4 = ADC_GetAdcValue(AD0_2); //Y AXIS
    delta_y = adcValue1 - adcValue4;
    if (delta_y > thx_y)
    {
     BUZZER_DIR |= BUZZER;
     BUZZER_SET |= BUZZER;
     a=2;//need to print this value in main function
     sprintf((char *)buf, "a:%d ",a);
     lcd_putstring(0, (char *)buf);
    }
/////////////////////////////////////////
    adcValue5 = ADC_GetAdcValue(AD0_4); //Z AXIS
    delta_z = adcValue2 - adcValue5;
    if (delta_z > thx_z)
    {
     BUZZER_DIR |= BUZZER;
     BUZZER_SET |= BUZZER;
    a=3;//need to print this value in main function
     sprintf((char *)buf, "a:%d ",a);
    lcd_putstring(0, (char *)buf);
    }
 
return a;
 
}