Thread: handling overflow, underflow etc

Hi, I have written a small function that can (I think) deal with
overflow/underflow while adding integers and divide by zero problem.
Can some one please tell me if I have done it correctly ? Would it be
safe to extend it to double precision floating point numbers since we
know that there is always some margin for error while adding floating
point numbers ? What other functions should I look to implement for my
project which needs heavy numerical computation ?

Code:

#include <stdio.h>
#include <limits.h>

int add_chk(int a, int b)
{
    if (b > 0)
    {
        if (a > INT_MAX - b)
        {
            fprintf(stderr, "Overflow error\n");
            return (INT_MAX);
        }
    }

    if (b < 0)
    {
        if (a < INT_MIN - b)
        {
            fprintf(stderr, "Underflow error\n");
            return (INT_MIN);
        }
    }

    return (a + b);

}

int div_chk(int a, int b)
{
    if (b == 0)
    {
        fprintf(stderr, "Division by zero attempted\n");
        return (INT_MAX);
    }

    return (a/b);

}

int main(void)
{
    int i;
    int x, y;

    clrscr();
    printf("Enter two numbers\n");
    if (scanf("%d %d", &x, &y) != 2)
    {
      fprintf(stderr, "Error in user input\n");
      return (1);
    }

    if  ((x < INT_MAX && x > INT_MIN) && ( y < INT_MAX && y > INT_MIN))
    {
        i = add_chk(x, y);
        printf("Sum: %d\n", i);
        i = div_chk(x, y);
        printf("Div: %d\n", i);
    }
    else
    {
      fprintf(stderr, "Values entered are out of range\n");
      return (1);
    }
    return (0); 
}