good day please its urgent
I wrote a code today and i which to set minimum buy and maximum buy but after setting the code its not functioning well when i tested it on tesnet kindly tell me what is wrong in my code
pragma solidity ^0.4.24;
// ----------------------------------------------------------------------------
// 'Yfkp3r' Smart Contract
//
// OwnerAddress : 0xcD6d0eF089FC8D849580bB59896dDcDCD4047940
// Symbol : Yfkp3r
// Name : Yfkp3r Token
// Total Supply : 4500
// Decimals : 18
// Copyrights of 'Yfkp3rToken' With 'Yfkp3r' Symbol November 1, 2020.
// The MIT Licence.
//
// Prepared and Compiled by: HASSAN ISA
// ----------------------------------------------------------------------------
library SafeMath {
function add(uint a, uint b) internal pure returns (uint c) {
c = a + b;
require(c >= a);
}
function sub(uint a, uint b) internal pure returns (uint c) {
require(b <= a);
c = a - b;
}
function mul(uint a, uint b) internal pure returns (uint c) {
c = a * b;
require(a == 0 || c / a == b);
}
function div(uint a, uint b) internal pure returns (uint c) {
require(b > 0);
c = a / b;
}
}
// ----------------------------------------------------------------------------
// Ownership contract
// _newOwner is address of new owner
// ----------------------------------------------------------------------------
contract Owned {
address public owner;
event OwnershipTransferred(address indexed _from, address indexed _to);
constructor() public {
owner = 0xcD6d0eF089FC8D849580bB59896dDcDCD4047940;
}
modifier onlyOwner {
require(msg.sender == owner);
_;
}
// transfer Ownership to other address
function transferOwnership(address _newOwner) public onlyOwner {
require(_newOwner != address(0x0));
emit OwnershipTransferred(owner,_newOwner);
owner = _newOwner;
}
}
// ----------------------------------------------------------------------------
// ERC Token Standard #20 Interface
// ----------------------------------------------------------------------------
contract ERC20Interface {
function totalSupply() public constant returns (uint);
function balanceOf(address tokenOwner) public constant returns (uint balance);
function allowance(address tokenOwner, address spender) public constant returns (uint remaining);
function transfer(address to, uint tokens) public returns (bool success);
function approve(address spender, uint tokens) public returns (bool success);
function transferFrom(address from, address to, uint tokens) public returns (bool success);
event Transfer(address indexed from, address indexed to, uint tokens);
event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}
// ----------------------------------------------------------------------------
// ERC20 Token, with the addition of symbol, name and decimals and an
// initial fixed supply
// ----------------------------------------------------------------------------
contract Yfkp3rToken is ERC20Interface, Owned {
using SafeMath for uint;
string public symbol;
string public name;
uint8 public decimals;
uint public _totalSupply;
uint256 public _minbuy;
uint256 public _maxbuy;
uint public RATE;
uint public DENOMINATOR;
bool public isStopped = false;
mapping(address => uint) balances;
mapping(address => mapping(address => uint)) allowed;
event ChangeRate(uint256 amount);
modifier onlyWhenRunning {
require(!isStopped);
_;
}
// ------------------------------------------------------------------------
// Constructor
// ------------------------------------------------------------------------
constructor() public {
symbol = "Yr";
name = "YToken";
decimals = 18;
_totalSupply = 4500 * 10**uint(decimals);
_minbuy = 10 ** 17;
_maxbuy = 1 ** 18;
balances[owner] = _totalSupply;
RATE = 5000; // 1 ETH = 5 Yfkp3r
DENOMINATOR = 1000;
emit Transfer(address(0), owner, _totalSupply);
}
// ----------------------------------------------------------------------------
// requires enough gas for execution
// ----------------------------------------------------------------------------
function() public payable {
buyTokens();
}
// ----------------------------------------------------------------------------
// Function to handle eth and token transfers
// tokens are transferred to user
// ETH are transferred to current owner
// ----------------------------------------------------------------------------
function buyTokens() onlyWhenRunning public payable {
require(msg.value > 0);
uint tokens = msg.value.mul(RATE).div(DENOMINATOR);
require(balances[owner] >= tokens);
balances[msg.sender] = balances[msg.sender].add(tokens);
balances[owner] = balances[owner].sub(tokens);
emit Transfer(owner, msg.sender, tokens);
owner.transfer(msg.value);
}
// ------------------------------------------------------------------------
// Total supply
// ------------------------------------------------------------------------
function totalSupply() public view returns (uint) {
return _totalSupply;
}
// ------------------------------------------------------------------------
// Get the token balance for account `tokenOwner`
// ------------------------------------------------------------------------
function balanceOf(address tokenOwner) public view returns (uint balance) {
return balances[tokenOwner];
}
// ------------------------------------------------------------------------
// Transfer the balance from token owner's account to `to` account
// - Owner's account must have sufficient balance to transfer
// - 0 value transfers are allowed
// ------------------------------------------------------------------------
function transfer(address to, uint tokens) public returns (bool success) {
require(to != address(0));
require(tokens > 0);
require(balances[msg.sender] >= tokens);
balances[msg.sender] = balances[msg.sender].sub(tokens);
balances[to] = balances[to].add(tokens);
emit Transfer(msg.sender, to, tokens);
return true;
}
// ------------------------------------------------------------------------
// Token owner can approve for `spender` to transferFrom(...) `tokens`
// from the token owner's account
//
// ------------------------------------------------------------------------
function approve(address spender, uint tokens) public returns (bool success) {
require(spender != address(0));
require(tokens > 0);
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
return true;
}
// ------------------------------------------------------------------------
// Transfer `tokens` from the `from` account to the `to` account
//
// The calling account must already have sufficient tokens approve(...)-d
// for spending from the `from` account and
// - From account must have sufficient balance to transfer
// - Spender must have sufficient allowance to transfer
// ------------------------------------------------------------------------
function transferFrom(address from, address to, uint tokens) public returns (bool success) {
require(from != address(0));
require(to != address(0));
require(tokens > 0);
require(balances[from] >= tokens);
require(allowed[from][msg.sender] >= tokens);
balances[from] = balances[from].sub(tokens);
allowed[from][msg.sender] = allowed[from][msg.sender].sub(tokens);
balances[to] = balances[to].add(tokens);
emit Transfer(from, to, tokens);
return true;
}
// ------------------------------------------------------------------------
// Returns the amount of tokens approved by the owner that can be
// transferred to the spender's account
// ------------------------------------------------------------------------
function allowance(address tokenOwner, address spender) public view returns (uint remaining) {
return allowed[tokenOwner][spender];
}
// ------------------------------------------------------------------------
// Increase the amount of tokens that an owner allowed to a spender.
//
// approve should be called when allowed[_spender] == 0. To increment
// allowed value is better to use this function to avoid 2 calls (and wait until
// the first transaction is mined)
// _spender The address which will spend the funds.
// _addedValue The amount of tokens to increase the allowance by.
// ------------------------------------------------------------------------
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
require(_spender != address(0));
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
// ------------------------------------------------------------------------
// Decrease the amount of tokens that an owner allowed to a spender.
//
// approve should be called when allowed[_spender] == 0. To decrement
// allowed value is better to use this function to avoid 2 calls (and wait until
// the first transaction is mined)
// _spender The address which will spend the funds.
// _subtractedValue The amount of tokens to decrease the allowance by.
// ------------------------------------------------------------------------
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
require(_spender != address(0));
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
// ------------------------------------------------------------------------
// Change the ETH to IO rate
// ------------------------------------------------------------------------
function changeRate(uint256 _rate) public onlyOwner {
require(_rate > 0);
RATE =_rate;
emit ChangeRate(_rate);
}
// ------------------------------------------------------------------------
// _to The address that will receive the minted tokens.
// _amount The amount of tokens to mint.
// A boolean that indicates if the operation was successful.
// ------------------------------------------------------------------------
function mint(address _to, uint256 _amount) onlyOwner public returns (bool) {
require(_to != address(0));
require(_amount > 0);
uint newamount = _amount * 10**uint(decimals);
_totalSupply = _totalSupply.add(newamount);
balances[_to] = balances[_to].add(newamount);
emit Transfer(address(0), _to, newamount);
return true;
}
// ------------------------------------------------------------------------
// function to stop the ICO
// ------------------------------------------------------------------------
function stopPRESALE() onlyOwner public {
isStopped = true;
}
// ------------------------------------------------------------------------
// function to resume ICO
// ------------------------------------------------------------------------
function resumePRESALE() onlyOwner public {
isStopped = false;
}
}