tax program

#include <iostream>
#include <string>
#include <cmath>

using namespace std;

int getChildren ();

double taxAmount(int, double, double, int);

void getData ();

int main ()

{
        getData();
        return double;
}

void getData ()

{
        char status, answer;
        int numChildren;
        double salary, pensionAmount, deductAmount;
        int numPeople, standardExemption;
        double tax;

        cout<<"Enter 'm'arried or 's'ingle:";
        cin>>status;
        cout<<endl;

        if (status=='m'||status=='M')
        {
                numChildren=getChildren();
                standardExemption=7000;

                cout<<"Do both spouses earn an income? Enter 'Y'es or 'N'o: ";
                cin>>answer;
                cout<<endl;

                if (answer=='y'||answer=='Y')
                {
                        cout<<"Please enter combined salary: ";
                        cin>>salary;
                        cout<<endl;
                }
                else if (answer=='n'||answer=='N')
                {
                        cout<<"Please enter your salary: ";
                        cin>>salary;
                        cout<<endl;
                }
                numPeople=2+numChildren;
        }
        else
        {
                cout<<"Please enter your salary: ";
                cin>>salary;
                cout<<endl;
                standardExemption=4000;
                numPeople=1;
        }

        cout<<"Please enter pension plan amount: ";
        cin>>pensionAmount;
        cout<<endl;

        tax = taxAmount(numPeople, salary, pensionAmount, standardExemption);
}

int getChildren ()

{
        int children;

        cout<<"Enter number of children under 14: ";
        cin>>children;
        cout<<endl;

        return children;

}

double taxAmount(int numPeople, double salary, double pensionAmount, int standardExemption) //You need to name these parameters, or you won't be able to use them
{

 int amountoftax;

        double deductionPerNumPeople = (numPeople*1500.00);

        if(salary <= 15000.00)
        {
                amountoftax = salary - ((deductionPerNumPeople + pensionAmount + standardExemption) * 0.15);
        }
        else if(salary > 15000.00 && salary <= 40000.00)
        {
                amountoftax = 2250.00 + ((deductionPerNumPeople + pensionAmount + standardExemption - 15000.00) * 0.25);
        }
        else if(salary > 40000.00)
        {
                amountoftax = 8460.00 + ((deductionPerNumPeople + pensionAmount + standardExemption - 40000.00) * 0.35);

                cout<<"Your tax amount is: "<<tax<<endl;
        }

        return 0; //Not returning anythign useful
}