Using JavaScript Array.prototype.map for http://pastie.org/pastes/10094244/text?key=rxbt7tdkh0yyrngilvraw

gistfile1.js

function getString(str, offset) {
    return str.split('')
        .map(function(ch) {
            return String.fromCharCode(ch.charCodeAt(0) + offset);
        })
        .join('');
}