Binary-Decimal and Decimal-Hexadecimal Conversion

#include<conio.h>
#include<stdio.h>
#include<math.h>
#include<string.h>
#define max 10
 void main()
  {
   clrscr();
   long bin;
   char hdec[max];
   int i,x,n,fb,dec;
   do
   {
   printf("Enter the Binary No. :- ");
   scanf("%ld",&bin);
   i = fb = dec = 0;
   while(bin)
     {
       n = bin % 10;
       dec += n*pow(2,i);
       i++;
       bin /= 10;
       if( n != 0 && n != 1)
{
  fb = 1;
  break;
}
     }
    if(fb == 1)
     printf("\n\n\t\t ERROR :- This is not a binary number .. Retype Again !! \n\n");
   }while(fb == 1);
   i = 0;
   printf("\n\n\t Its decimal equivalent is :- %d",dec);
   printf("\n\n\t n Its hexadecimal equivalent is :- ");
   while(dec != 0 )
    {
      n = dec%16;
       if(n==10) hdec[i] = 'A';
       else if(n==11)    hdec[i] = 'B';
       else if(n==12)    hdec[i] = 'C';
       else if(n==13)    hdec[i] = 'D';
       else if(n==14)    hdec[i] = 'E';
       else if(n==15)    hdec[i] = 'F';
       else         hdec[i] = n+48 ;
       i++;
      dec /= 16;
    }
   hdec[i]='\0';
   strrev(hdec);
   puts(hdec);

   getch();
  }