string obfuscate + deobfuscate

obfuscate.js

String.prototype.obfuscate = function()
{
    var temp = '';
    for(i = 0; i < this.length; i++){temp += String.fromCharCode(this.charCodeAt(i)+parseInt((i+1)%5))};
    return temp;
}

String.prototype.deobfuscate = function()
{
    var temp = '';
    for(i = 0; i < this.length; i++){temp += String.fromCharCode(this.charCodeAt(i)-parseInt((i+1)%5))};
    return temp;
}