Deployed a Simple Online Wallet on XinFin XDC Network

address payable internal owner;
string internal ownerName;
string internal dappsName;
uint256 internal reserveToken;
uint32 internal decimals;
event TransferToken(address source, address destination, uint amount); // BC will log event transferToken
struct account {
    string name;
    uint256 token;
}
mapping(address => account) internal myAccount;
constructor () public {
    owner = msg.sender;  // the one submited this smart contract into BC
    ownerName = "iExploTech BC Tutorial";
    dappsName = "Simple Online Wallet Tutorial";
    decimals = 3; // 3 precision point of fraction number
    reserveToken = 1000000 * 10**uint(decimals);  // 1 Million Tokens with 3 precision point of fraction number. e.g. 0.001 cent
    emit TransferToken(address(0), owner, reserveToken);  // publish generated tokens to BC logs
}
modifier onlyOwner() {
    require(msg.sender == owner); // only smart contract owner is authorized to execute functions
    _;
}
// require gas to execute, only smart contract owner is authorized to add new account and disperse new tokens
function addAccount( string memory newName, address newAddress, uint256 newToken) public onlyOwner {   
    if(newToken <= reserveToken) {
        myAccount[newAddress].name = newName;
        myAccount[newAddress].token = newToken;
        reserveToken = sub(reserveToken, newToken); //reserveToken = reserveToken - newToken;
    } 
    else
        revert("Not Enough Reserve Token"); // will undo all state changes, it will refund any remaining gas to the caller
}
// require gas to execute, only smart contract owner is authorized to change account name
function changeAccountName( string memory newName, address newAddress) public onlyOwner {
        myAccount[newAddress].name = newName;
}
// require gas to execute, only smart contract owner is authorized to disperse additional tokens
function disperseToken(address newAddress, uint256 newToken) public onlyOwner {   
    if(newToken <= reserveToken  && newToken!= 0) {
        myAccount[newAddress].token = newToken;
        reserveToken = sub(reserveToken, newToken); //reserveToken = reserveToken - newToken;
    } 
    else
        revert("Not Enough Reserve Token"); // will undo all state changes, it will refund any remaining gas to the caller
}
function transferToken(address newRecipient, uint256 newToken) public {
    if(myAccount[msg.sender].token >= newToken && newToken!= 0) {
        myAccount[newRecipient].token =  add(myAccount[newRecipient].token, newToken); // myAccount[newRecipient].token = myAccount[newRecipient].token + newToken;
        myAccount[msg.sender].token = sub(myAccount[msg.sender].token, newToken); // myAccount[msg.sender].token = myAccount[msg.sender].token - newToken;
        emit TransferToken(msg.sender, newRecipient, newToken);  // publish transferred tokens to BC logs
    } else
        revert("Not Enough Token"); // will undo all state changes, it will refund any remaining gas to the caller
}
function displayReserveToken() public onlyOwner view returns (uint256 ReserveToken) {
    return reserveToken;
}
function displayMyAccountInfo () public view returns (string memory Name, address Account, uint256 Eth_Wei, uint256 Token) {
    return (myAccount[msg.sender].name, msg.sender, msg.sender.balance, myAccount[msg.sender].token);
}
function displayOwner() public view returns (string memory Name, address Account, string memory DAppsName) {
    return (ownerName, owner,  dappsName);
}
// Destroy smartcontract in blockchain. This smart contract cannot be accessed after this command. Old data still exist in blockchain.
function kill() public onlyOwner {
        selfdestruct(owner);
}