public static void insertionSort(ArrayList <Employee> employee)
    {
        int i,j;
        for(i = 0; i < employee.size(); i++)
        {
            Employee temp = employee.get(i);
            j = i - 1;
            while (j >= 0 && employee.get(j).getLastName().compareToIgnoreCase(temp.getLastName()) > 0)
            {
                employee.set(j + 1, employee.get(j));
                j--;
            }
            employee.set(j + 1, temp);
        }
    }