Encrypt/Decrypt Dynamic

I'm a genius.

by Mike Gleeson

HTML

<textarea id='inputEncrypt' type='text' placeholder='Type Message...'></textarea>
<input id='encrypt' type='button' value='Encrypt Message'/>
<input id='decrypt' type='button' value='Decrypt Message'/>
<span id='test'/>

CSS

#test {
    font-size:32px;
    color: red;
    height:200px;
    width:100%;
    display:block;
}

#inputEncrypt {
    display:block;
    height:200px;
    width:100%;
}

JavaScript

function encrypt(message) {
    var _length = message.length;
    var _encryptedRet = "";
    var _prevLength = 0;
    for(var i = 0; i < _length; i++) {
        var _code = message.charCodeAt(i);
        _code+=_length;
        if(_code > 255) _code -= 222;
        _encryptedRet+= String.fromCharCode(_code);
        if(_prevLength == _encryptedRet.length) alert("FAILURE at character code"+_code);
        _prevLength = _encryptedRet.length;
    }
    
    return _encryptedRet;
}

function decrypt(message) {
    var _length = message.length;
    var _decryptedRet = "";
    for(var i = 0; i < _length; i++) {
        var _code = message.charCodeAt(i);
        _code-=_length;
        if(_code < 0) _code += 222;
        _decryptedRet+= String.fromCharCode(_code);
    }
    
    return _decryptedRet;   
}

var _span = $("#test");

var _input = $("#inputEncrypt");

var _encryptBtn = $("#encrypt");

var _decryptBtn = $("#decrypt");

_encryptBtn.click(function() {
    _span.html(encrypt(_input.val()));
});

_decryptBtn.click(function() {
    _span.text(decrypt(_input.val()));
});