Program to generate magic square

Program:

#include<stdio.h>
void main()
{
    int n, i, j, c, a[9][9];
    clrscr();
    printf("Enter the size of the magic square : ");
    scanf("%d", &n);
    if (n % 2 == 0)
    {
        printf("\nMagic square is not possible");
        goto end;
    }
    printf("\nThe magic square for %d x %d is :\n\n", n, n);
    j = (n + 1) / 2;
    i = 1;
    for(c = 1 ; c <= n * n ; c++)
    {
        a[i][j] = c;
        if(c % n == 0)
        {
            i = i + 1;
            goto loop;
        }
        if(i == 1)
        i = n;
        else
        i = i - 1;
        if(j == n)
        j = 1;
        else
        j = j + 1;
        loop : ;
    }
    for (i = 1 ; i <= n ; i++)
        {
        for (j = 1 ; j <= n ; j++)
        {
            printf("%d\t", a[i][j]);
        }
        printf("\n\n");
    }
    end : ;
    getch();
}

Output:

Case: 1

Enter the size of the magic square : 3
The magic square for 3 x 3 is :
8 1 6
3 5 7
4 9 2

Case: 2

Enter the size of the magic square : 4
Magic square is not possible