/// <summary>
/// update Contract
/// </summary>
/// <param name="myContract"></param>
public void UpdateContract(Contract myContract)
{
int index = myXML.GetContractList().FindIndex(x => x.TransactionNumber == myContract.TransactionNumber);
if (index == -1)
{
throw new Exception("Contract not exist");
}
myXML.UpdateContract(myContract);
}