Someone

#include <iostream>
#include <iomanip>

using namespace std;

double saleAmountFunc ();
double calCommission (double saleAmount);

int main ()
{
	for (;;)
	{
		double saleAmount, commission;

		//cout << "Enter the value of sale amount: ";
		//cin >> saleAmount;
		saleAmount = saleAmountFunc();
		if (saleAmount <0)
			break;
		if (saleAmount >0 || saleAmount <999)
			commission = .035 * saleAmount;
		else if (saleAmount >1000 || saleAmount <1999)
			commission = .04 * saleAmount;
		else if (saleAmount >2000 || saleAmount <2999)
			commission = .045 * saleAmount;
		else if(saleAmount > 3000)
			commission = .05 * saleAmount;

		cout << setiosflags(ios::showpoint)
		<< setiosflags(ios:: fixed)
		<< setprecision(2)
		<< "The commission is $" << commission << endl;
	}
	return 0;
}

double saleAmountFunc()
{
	double saleAmount;
	cout << "Enter the value of sale amount: ";
	cin >> saleAmount;
	return saleAmount;
}

double calCommission (double saleAmount)
{
	double commission;
	saleAmount = saleAmountFunc();
	if (saleAmount >0 || saleAmount <999)
		commission = .035 * saleAmount;
	else if (saleAmount >1000 || saleAmount <1999)
		commission = .04 * saleAmount;
	else if (saleAmount >2000 || saleAmount <2999)
		commission = .045 * saleAmount;
	else if(saleAmount > 3000)
		commission = .05 * saleAmount;
	return saleAmount;
}