Quick Question

[Purples]

So I'm programming another calculator, and this time I'm trying to do exponents (ex. 3^4=81).

#include <iostream>
using namespace std;
int main ()
{
    int w=1;
    do {
        cout << "\nEnter an expression.\n"; //instructions for the user
        cout << "Key: \n";
        cout << "* = multiply\n";
        cout << "/ = divide\n";
        cout << "+ = add\n";
        cout << "- = subtract\n";
        cout << "^ = x to the yth power\n";
        cout << "Enter your expression.\n";
        int x,z;
        char y;
        cin >> x >> y >> z; //get the expression
        switch (y) {
        case '+': //calculate answer(s)
            cout << "The answer is " << x+z << ".\n";
            break;
        case '-':
            cout << "The answer is " << x-z << ".\n";
            break;
        case '*':
            cout << "The answer is " << x*z << ".\n";
            break;
        case '/':
            cout << "The answer is " << x/z << ".\n";
        case '^':
            for (z; z >= 2; z=z-1)
            {
                int Q;
                Q=x*x;
            }
            cout << "The answer is " << x << ".\n";
            break;
        default :
            cout << "The expression is invalid.\n";
            break;
        }
        cout << "To run function again, press 1.  Otherwise, press 0.\n"; //Optional Continuation
        cin >> w;
    } while (w==1);
    cin.get();
}

This program runs fine, but when I try to do the exponent, I get the wrong number. Usually it happens like this:
3^4 = 3
6^2 = 6
etc.
So basically I just get my x value back. How do I fix this?
Thanks

[laserlight]

Notice that you don't change x in that part of the program, so the value of x remains the same.