pragma solidity ^0.4.11;
contract tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData); }

contract MessageToken {
    /* Public variables of the token */
    string public standard = 'Token 0.1';
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;
    address owner;
    address EMSAddress;

    /* This creates an array with all balances */
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    /* This generates a public event on the blockchain that will notify clients */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /* This notifies clients about the amount burnt */
    event Burn(address indexed from, uint256 value);

    /* Initializes contract with initial supply tokens to the creator of the contract */
    function MessageToken() {
        balanceOf[this] = 10000000000000000000000000000000000000;              // Give the contract all initial tokens
        totalSupply = 10000000000000000000000000000000000000;                        // Update total supply
        name = "Messages";                                   // Set the name for display purposes
        symbol = "\u2709";                               // Set the symbol for display purposes
        decimals = 0;                            // Amount of decimals for display purposes
        owner = msg.sender;
    }

    /* Send coins */
    function transfer(address _to, uint256 _value) {
        if (_to != address(this)) throw;                     // Prevent sending message tokens to other people
        if (balanceOf[msg.sender] < _value) throw;           // Check if the sender has enough
        if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
        balanceOf[msg.sender] -= _value;                     // Subtract from the sender
        balanceOf[_to] += _value;                            // Add the same to the recipient
        Transfer(msg.sender, _to, _value);                   // Notify anyone listening that this transfer took place
    }

    /* Allow message contract to spend some tokens in your behalf */
    function approve(address _spender, uint256 _value)
        returns (bool success) {
            if(msg.sender == owner){
                EMSAddress = _spender;
                allowance[this][_spender] = _value;
                return true;
            }
    }
    
    function register(address _address)
        returns (bool success){
            if(msg.sender == EMSAddress){
                allowance[_address][EMSAddress] = totalSupply;
                return true;
            }
        }

    /* A contract attempts to get the coins */
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        if (_to == 0x0) throw;                                // Prevent transfer to 0x0 address. Use burn() instead
        if (balanceOf[_from] < _value) throw;                 // Check if the sender has enough
        if (balanceOf[_to] + _value < balanceOf[_to]) throw;  // Check for overflows
        if (_value > allowance[_from][msg.sender]) throw;     // Check allowance
        balanceOf[_from] -= _value;                           // Subtract from the sender
        balanceOf[_to] += _value;                             // Add the same to the recipient
        allowance[_from][msg.sender] -= _value;
        Transfer(_from, _to, _value);
        return true;
    }
    
    function getBalance(address _address) constant returns (uint256 balance){
        return balanceOf[_address];
    }
}