im facing a problem with adc in lpc 2138.

The output is varying continously in my lcd even there is no change in the adc input.i want a code to display the output in lcd.please give any suggestions to my code.

#include <lpc21xx.h> /* LPC2200 definitions */
#include <stdio.h> /* standard I/O .h-file */
//#define VREF 3
int i,j; long val,adc_val; unsigned char d1=0,d2=0,d3=0,d4=0,d5=0,d6=0;

//extern void init_serial (void);

void delay(void);
void adc_init(void);
void adc_read(void);

void data(void);
void lcddata(unsigned char c);
void lcdcmd(unsigned char c);
void lcdinit(void);
void lcddisplay(unsigned char *ptr);
void message(unsigned char k,unsigned char *ptr1);

int main()
{ PINSEL0=0X00000000;
PINSEL1=0X00400000;
IODIR0=0X70000000;
IODIR1=0X00ff0000;

lcdinit();
delay();
//lcdcmd(0x01);
//delay(1000);
message(0x80,"ir measurement"); adc_init(); while(1)
{ adc_read();
data();
delay();
} }

void adc_init(void)
{ //PINSEL1=0x01000000;
ADCR&=0x00000000;
VPBDIV = 0x02; /*Set the Pclk to 30 Mhz */
ADCR|= 0x00210601;
}

void adc_read(void)
{

ADCR|= 0x01000000; /* Start A/D Conversion */
delay();
delay();
delay();

while ((ADDR & 0x80000000) == 0); /*Wait for the conversion to complete */
val=ADDR;
adc_val = ((val>> 6) & 0x00FF); /*Extract the A/D result */
}

void delay(void)
{ for(i=0;i<=75;i++)
for(j=0;j<=1000;j++);
}

void lcddata(unsigned char c)
{ IOCLR1=0x00ff0000;
IOSET0=0x10000000; // rs =1 p0.28
IOCLR0=0x20000000; // rw =0 p0.29
IOSET0=0x40000000; // en=1 p0.30
IOSET1 = c<<16;
delay();
IOCLR0=0x40000000; //en=0 p0.30
}

void lcdcmd(unsigned char c)
{ IOCLR1=0x00ff0000;
IOCLR0=0x10000000; // rs =0 p0.28
IOCLR0=0x20000000; // rw =0 p0.29
IOSET0=0x40000000; // en=1 p0.30
IOSET1 = c<<16;
delay();
IOCLR0=0x40000000; //en=0 p0.30
} void lcdinit()
{ lcdcmd(0x38);
delay();
lcdcmd(0x01);
delay();
lcdcmd(0x0c);
delay();
//lcdcmd(0x01);
//delay();
lcdcmd(0x80);
delay();
}

void lcddisplay(unsigned char *ptr)
{ while(*ptr)
{ lcddata(*ptr);
ptr++;
} }

void message(unsigned char k,unsigned char *ptr1)
{ lcdcmd(k);
delay();
lcddisplay(ptr1);
}

void data(void)
{

d1=adc_val/10;
d2=adc_val%10;
d3=d1/10;
d4=d1%10;

//d5=d3/10;
//d6=d3%10;

lcdcmd(0xc0); delay(); lcddata(d3+0x30);
//lcddata(d6+0x30);
lcddata(d4+0x30);
lcddata(d2+0x30);

}