an error handling code doubt

[rickenjus]

I want this code to call generic catch block whenever any special character(eg. !,@,#,$,%,&,*, etc) is enetered in numerator or denominator. So what code should I add to this.
Any help would be appreciated. Thanks.

#include <iostream>

using namespace std;

int main()
{
    try                                                // generic catch block
    {  
       int num, den;
       double division;
       try
       {
         cout << "\n enter numerator(+ve no. only): ";
         cin >> num ;
         if (num<0) throw 3.2 ;
       }    
    
       catch(double m)
       {
          cout << "\n ERROR: numerator should be positive ";
          num = -num ;
          cout << "\n\n So your new numerator is: " << num;
       }         
    
       try
       {
          cout << "\n\n enter denominator: ";
          cin >> den ;
          if (den==0) throw 1;
       }
    
       catch(int n)
       {
          cout << "\n ERROR: You can't divide a no. by zero, enter another no: ";
          cin >> den;
       }

       division = double(num)/den;
       cout << "\n result is: " << division << "\n\n ";
    }
    
    catch(...)                              // Generic catch block
    {
       cout << "/n/n Unexpected Error: Contact your software provider";
    }  
    system("PAUSE");
    return EXIT_SUCCESS;
}

[thines01]

Are you saying you only want to allow numeric values and ignore all others?

[rickenjus]

Are you saying you only want to allow numeric values and ignore all others?

Yes, exactly that.

[thines01]

Have you looked at these?:
http://www.daniweb.com/software-development/cpp/threads/279409
http://www.devhardware.com/forums/programming-82/code-for-allowing-only-integers-in-c-31551.html

Using the example at the second link:

#include <iostream>
using namespace std;

int main(void)
{
   int intNumerator=0;
   int intDenominator=0;

   cout << "Enter the Numerator: ";
   while(!(cin >> intNumerator))
   {
      cin.clear(); // When cin fails, clear the failed flag.
      while(cin.get() != '\n'){} // This line is basically a loop the cleans out anything that is left over in the input stream.
      cout << "Try Again: ";
   }

   cout << "Enter the Denominator: ";
   while(!(cin >> intDenominator))
   {
      cin.clear();
      while(cin.get() != '\n'){}
      cout << "Try Again: ";
   }

   return 0;
}