PIC18F4520 4 Digit 7 Segment using 74hc595 Shift Register

#define SCLK  PORTC.B0         //Serial Clock
#define SDOUT PORTC.B1        //Serial Data Out
#define SDIN  PORTC.B2         //Serial Data In
#define CS0   PORTC.B3         //Chip Select
#define CS1   PORTC.B4
//---------------------------DIRECTION------------------------------------------
#define SCLK_dir   TRISC.B0
#define SDOUT_dir  TRISC.B1
#define SDIN_dir   TRISC.B2
#define CS0_dir    TRISC.B3
#define CS1_dir    TRISC.B4
//------------------------------------------------------------------------------

unsigned int size,offset,Rx,j,pos,count,temp, adc_value; //store output value from Analog Read function
char _data=0;
char* strNum[10];            //Character buffer (see itoa prototype)
//-------------------------Common Anode-----------------------------------------
                                // 0 , 1  ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9
unsigned const char digit[10] = {0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};
unsigned const char column[8] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80};
unsigned const char noDigits = 4;

void SPI_init(void)
{
  SCLK_dir = 0;
  SDOUT_dir = 0;
  SDIN_dir = 1;
  CS0_dir  = 0;
  CS1_dir  = 0;
}
//--------------------------TX: transmit data-----------------------------------//
void SPI_write(char send)
{
  for(j=0;j<8;j++)
  {
    SCLK = 0;
    SDOUT = ((send << j) & 0x80) ? 1 : 0;   //MSB first.
    SCLK = 1;
  }
}
//--------------------------RX: recieve data------------------------------------//
char SPI_read(void)
{

  for(Rx = 0 ; Rx < 8 ; Rx++ )
  {
    SCLK = 0;
    _data += (SDIN << (7-Rx));  //MSB first.
    SCLK = 1;
  }

  return _data;
}

void SR_dataSend(char _data)
{
  CS0 = 0;
  SPI_write(_data);
  CS0 = 1;
}
//------------------------------------------------------------------------------
void SR_colSend(char col)
{
  CS1 = 0;
  SPI_write(col);
  CS1 = 1;
}
//------------------------------------------------------------------------------
void SR_colSelect(char col)
{
  SR_colSend(column[col]);    //Turn particular column On
  Delay_ms(5);
  SR_colSend(0);              //...then turn it Off
}
void segment_display(int number)
{

  IntToStr(number,strNum);    //Change from Int to C-String (stdlib function)

  size = strlen(strNum);               //<string.h> function
  offset = noDigits - size;

  for(pos=0; pos < size; pos++)
  {
    char index = strNum[pos] - 48;          //Decimal 48 is 0 in ASCII

    SR_dataSend(digit[index]);
    SR_colSelect(pos + offset);
  }
}



void main() {
ADCON0 = 0x00;
ADCON2 = 0x26;    //
OSCCON = 0x74;
// OSCTUNE = 0x40;   // osctune bit 6 is used to activate PLL for internal oscillator
TRISA  = 0x01;      /*set as input port*/
TRISC  = 0x00;

SPI_init();

while(1){

for(count=0; count<10000; count++)
    {
     segment_display(count);
     Delay_ms(20);
    }
count=0;
}
}