/// <summary>
/// removes an item from the the order
/// </summary>
/// <param name="orgPrice"> the orignal price for the item</param>
/// <param name="orgCalories"> the orignal calories for the item </param>
public void Remove(double orgPrice, uint orgCalories)
{
_subTotal -= orgPrice;
_totalCalories -= orgCalories;
NotifyPropertyChanged("_subTotal");
NotifyPropertyChanged("_tax");
NotifyPropertyChanged("_total");
NotifyPropertyChanged("_totalCalories");
orders.RemoveAt(currentListIndex);
parent.showMenu();
}