Purchase order Report Customization.

i am trying to add the Four More Columns in the Purchase order Line Level.

i am Customizing the SalesPurchLine  Map calcPrice2LineAmount Method .

Writing Below Code in that Method,

public AmountCur calcPrice2LineAmount(
Qty _qty,
boolean _forceLineAmountCalculation)
{
AmountCur lineAmount;

if (_qty)
{
lineAmount = PriceDisc::price2Amount(SalesPurchLine::pdsPrice(this),
this.PriceUnit,
this.discAmount(),
//srini
this.LocationdiscAmount(), //Customization 
this.RegionaldiscAmount(), //customization
_qty, // deliver now
this.SalesPurchQty,
this.Markup,
this.LocationdiscPercent(), //customization
this.RegionaldiscPercent(), //customization
this.discPercent(),
this.CurrencyCode,
this.LineAmount,
_forceLineAmountCalculation);
}

return lineAmount;
}

I am Getting this Error.

Argument 'currencyCode' is incompatible with the required type.

How to Solve this Error.