Need help(Rational no. class)

[Fatima Rizwan]

I have to create a class of rational numbers with the functionality that it can multiply,add,subtract and divide two rational numbers and give a simplified answer!
i am getting too many errors.
Here is the code:

#include<iostream.h>
#include<conio.h>

class rational
{

int num;
int denom;
int normal()
{
   int d, sign;
   sign = 1;
   if (top < 0) {
     sign = -1;
     top = -top;

   d = gcd(top, bottom);
   top = sign*(top / d);
   bottom = bottom / d;
}

unsigned int gcd(unsigned int n, unsigned int m) {
   if (n == 0) return m;
   if (m == 0) return n;
   while (m != n)
    {
      if (n > m) n = n - m;
      else m = m - n;
   }
   return n;
} 


public:
rational()
{
num=0;
denom=1;
}
rational (int)
{
cin>>num;
denom=1;
}
rational (int, int)
{
cin>>num;
cin>>denom;

}

void setNum(int)
{
cin>>num;
num.normal();
}

void setDenom(int)
{
cin>>denom;
denom.normal();
}

void add()
{rational add;
add.a=num*a.denom+a.num*denom;
add.b=denom*a.denom;
add.normal();
return add;
}

void sub()
{
rational sub;
sub.a=num*a.denom+a.num*denom;
sub.b=denom*a.denom;
sub.normal();
return sub;
}

void mult()
{
mult.a=num*a.num;
mult.b=denom*a.denom;
mult.normal();
return mult;
}

void div()
{
div.a=num*a.denom;
div.b=a.num*denom;
div.normal();
return div;
}
};
int main()
{
clrscr();
   rational x;
   rational a(3);
   rational b(3, 4);
   rational c(2, 4);
getch();
}