Interfacing Seven Segment Display.

#include<reg51.h>
#include<stdio.h>

sbit row0=P2^7; //assigning PORT-0 to read rows
sbit row1=P2^6; //assigning PORT-0 to read rows
sbit row2=P2^5; //assigning PORT-0 to read rows
sbit row3=P2^4; //assigning PORT-0 to read rows
sfr COL=0xA0;   //assigning PORT-2 to read colomns

sbit buz=P3^2;

sbit seg0=P3^0;
sbit seg1=P3^1;
sbit seg2=P3^2;
sbit seg3=P3^3;
sbit seg4=P3^4;
sbit seg5=P3^5;

void msdelay(unsigned int value);
int keypad();

char digi[10]={0x40,0xF9,0x24,0x30,0x19,0x12,0x02,0xF8,0x00,0x10};

unsigned char numbers[6]={"44444"};

void main()
{
unsigned int i;
while(1)
  {
   do
   {
    numbers[i]=keypad();
    i++;
   }
   while(i!=6);
   i=0;
    {
     P1=0x40;
    }
   }

}                       // MAIN ENDS HERE.



void msdelay(unsigned int value)
{
 unsigned int i,j;
 for(i=0;i<value;i++)
 for(j=0;j<100;j++);
}

int keypad()
{
        unsigned char dat[4][4]={'7','8','9','A',        // assigning key matrix
                                 '4','5','6','B',
                                 '1','2','3','-',
                                 '*','0','#','+',};

 unsigned char colloc,rowloc;
 COL=0x0F;
 row0=0;
 row1=0;
 row2=0;
 row3=0;
 while(1)
 {
  do
   {
    do
     {
      msdelay(90);
      colloc=COL;
      colloc&=0x0F;
     }
   while(colloc==0x0F);
   msdelay(90);
   colloc=COL;
   colloc&=0x0F;
   }
  while(colloc==0x0F);
  while(1)
  {
        row0=0;
        row1=1;
        row2=1;
        row3=1;
        msdelay(5);
        colloc=COL;
        colloc&=0x0F;
        if(colloc!=0x0F)
        {
         rowloc=0;
         break;
        }
         row0=1;
         row1=0;
         row2=1;
         row3=1;
         msdelay(5);
         colloc=COL;
         colloc&=0x0F;
         if(colloc!=0x0F)
         {
          rowloc=1;
          break;
         }
         row0=1;
         row1=1;
         row2=0;
         row3=1;
         msdelay(5);
         colloc=COL;
         colloc&=0x0F;
         if(colloc!=0x0F)
          {
           rowloc=2;
           break;
          }
        row0=1;
        row1=1;
        row2=1;
        row3=0;
        msdelay(5);
        colloc=COL;
        colloc&=0x0F;
        if(colloc!=0x0F)
        {
         rowloc=3;
         break;
        }
  }
if(colloc==0x0E)
  return(dat[rowloc][0]);
else if(colloc==0x0D)
  return(dat[rowloc][1]);
else if(colloc==0x0B)
  return(dat[rowloc][2]);
else
  return(dat[rowloc][3]);
}
}