public void complexDiscount(string discountArray, int storeID, string type, double percentage, string duration, int sessionID)
{
if (storeID < 0)
{
throw new ILLArgumentException("illegal store number");
}
if (sessionID < 0)
{
throw new NullReferenceException("session is a null reference");
}
db.complexDiscount(discountArray, storeID, type, percentage, duration, sessionID);
}