function buyTokenFromOwner() payable {
    require(msg.value >= price);
    if (msg.value > price) {
        msg.sender.transfer(msg.value.sub(price));
    }
    tokens[owner] = tokens[owner].sub(1);
    tokens[msg.sender] = tokens[msg.sender].add(1);
}

async buyToken() {
    let contractInstance = await TokenSaleContract.at(this.state.contractAddress);
    let name = await contractInstance.getName();
    await contractInstance.buyTokenFromOwner({ value: 107087936329796580 })
}