contract ERC20Token {

	mapping(address => uint256) public balances;

	function setSomeonesBalance(address owner, uint256 amount) public {
		balances[owner] = amount;
	}

	function transferTokensBetweenAddresses(address sender, address receiver, uint256 amount) public {
		balances[sender] -= amount;   // deduct/debit the sender's balance
		balances[receiver] += amount; // credit the reciever's balance
	}
}