private double CalculateGrossIncome(User taxPayer)
{
double retAmt = AnnualSalary.GetTaxableSalary();
retAmt -= GetHousingLoanInterestAmount();
if (OtherIncomes != null)
{
retAmt += OtherIncomes.CalculateTotalAmount();
}
retAmt -= (AnnualSalary.CalculateHraExemption(taxPayer.FromMetro, taxPayer.RentPaid) +
AnnualSalary.ProfessionalTax);
retAmt -= DonationsUnder80G.GetDeduction();
return(retAmt);
}