Trapping input

Im kinda newbish right now, but is there a way to stop people from entering the wrong type of input?

Code:

---


    main()
      {
        int a;
        cout << "Enter a number";
        cin >> a;
      }

---

If they enter a char for the input the program locks-up. Is there a way to catch those?

Code:

---

#include <iostream>

using namespace std;

int main()
{
        int a;
        bool flag = false;
        for (;;)
        {
                cout << "Enter a number: ";
                cin >> a;
                if (cin.fail())
                {
                        cin.clear();
                        cin.ignore(100, '\n');
                        cout << "Invalid Input!\n";
                }
                else
                        break;
        }
        cout << "Your number is: " << a << endl;
        return 0;
}

---

Thanks