// Vulnerability label: reentrancy
pragma solidity ^0.4.4;

    contract Token {

        /// @return total amount of tokens
        function totalSupply() constant returns (uint256 supply) {}

        /// @param _owner The address from which the balance will be retrieved
        /// @return The balance
        function balanceOf(address _owner) constant returns (uint256 balance) {}

        /// @notice send `_value` token to `_to` from `msg.sender`
        /// @param _to The address of the recipient
        /// @param _value The amount of token to be transferred
        /// @return Whether the transfer was successful or not
        function transfer(address _to, uint256 _value) returns (bool success) {}

        /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
        /// @param _from The address of the sender
        /// @param _to The address of the recipient
        /// @param _value The amount of token to be transferred
        /// @return Whether the transfer was successful or not
        function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}

        /// @notice `msg.sender` approves `_addr` to spend `_value` tokens
        /// @param _spender The address of the account able to transfer the tokens
        /// @param _value The amount of wei to be approved for transfer
        /// @return Whether the approval was successful or not
        function approve(address _spender, uint256 _value) returns (bool success) {}

        /// @param _owner The address of the account owning tokens
        /// @param _spender The address of the account able to transfer the tokens
        /// @return Amount of remaining tokens allowed to spent
        function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}

        event Transfer(address indexed _from, address indexed _to, uint256 _value);
        event Approval(address indexed _owner, address indexed _spender, uint256 _value);
        
    }



    contract StandardToken is Token {

        function transfer(address _to, uint256 _value) returns (bool success) {
            //Default assumes totalSupply can't be over max (2^256 - 1).
            //If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
            //Replace the if with this one instead.
            //if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
            if (balances[msg.sender] >= _value && _value > 0) {
                balances[msg.sender] -= _value;
                balances[_to] += _value;
                Transfer(msg.sender, _to, _value);
                return true;
            } else { return false; }
        }

        function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
            //same as above. Replace this line with the following if you want to protect against wrapping uints.
            //if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
            if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
                balances[_to] += _value;
                balances[_from] -= _value;
                allowed[_from][msg.sender] -= _value;
                Transfer(_from, _to, _value);
                return true;
            } else { return false; }
        }

        function balanceOf(address _owner) constant returns (uint256 balance) {
            return balances[_owner];
        }

        function approve(address _spender, uint256 _value) returns (bool success) {
            allowed[msg.sender][_spender] = _value;
            Approval(msg.sender, _spender, _value);
            return true;
        }

        function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
          return allowed[_owner][_spender];
        }

        mapping (address => uint256) balances;
        mapping (address => mapping (address => uint256)) allowed;
        uint256 public totalSupply;
    }


    //name this contract whatever you'd like
    contract EducationalDollarUtility is StandardToken {

        function () {
            //if ether is sent to this address, send it back.
            throw;
        }

        /* Public variables of the token */

        /*
        NOTE:
        The following variables are OPTIONAL vanities. One does not have to include them.
        They allow one to customise the token contract & in no way influences the core functionality.
        Some wallets/interfaces might not even bother to look at this information.
        */
        string public name;                   //fancy name: eg Simon Bucks
        uint8 public decimals;                //How many decimals to show. ie. There could 1000 base units with 3 decimals. Meaning 0.980 SBX = 980 base units. It's like comparing 1 wei to 1 ether.
        string public symbol;                 //An identifier: eg SBX
        string public version = 'H1.0';       //human 0.1 standard. Just an arbitrary versioning scheme.

    //
    // CHANGE THESE VALUES FOR YOUR TOKEN
    //

    //make sure this function name matches the contract name above. So if you're token is called TutorialToken, make sure the //contract name above is also TutorialToken instead of ERC20Token

        function EducationalDollarUtility(
            ) {
            balances[msg.sender] = 1000000000000000000000000000;               // Give the creator all initial tokens (100000 for example)
            totalSupply = 1000000000000000000000000000;                        // Update total supply (100000 for example)
            name = "Scholars Educational Dollar Utility";                                   // Set the name for display purposes
            decimals = 18;                            // Amount of decimals for display purposes
            symbol = "EDU";                               // Set the symbol for display purposes
        }

        /* Approves and then calls the receiving contract */
        function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
            allowed[msg.sender][_spender] = _value;
            Approval(msg.sender, _spender, _value);

            //call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
            //receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
            //it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
            if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { throw; }
            return true;
        }
    }