func (t *SimpleChaincode) Invoke(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
// Transaction makes payment of X units from A to B
var err error
X, err = strconv.Atoi(args[0])
Aval = Aval - X
Bval = Bval + X
ts, err2 := stub.GetTxTimestamp()
if err2 != nil {
fmt.Printf("Error getting transaction timestamp: %s", err2)
}
fmt.Printf("Transaction Time: %v,Aval = %d, Bval = %d\n", ts, Aval, Bval)
return nil, err
}