fixing this prime generator

The program below is meant to print prime numbers between the given set of numbers. But when i run, it just prints out one number instead of other numbers in between.

#include <iostream>

using namespace std;
int main()

{
int a;
int b;
int z = 0;
cout << "Enter an integer: ";
cin >> a;

cout << "Enter another number: ";
cin >> b;

for (int i=a; i<=b; i++)
{
    for (int j=2; j<i; j++)
    {

        if (i%j == 0)
        {
            z++ ;
            break;
        }
    }
    if (z == 0)
    {
        cout << i << endl;
    }
  }

}