OAuth nonce generator function from codebird, its bascially a random string generator.

oauth_nonce_gen.js

//https://github.com/jublonet/codebird-js/blob/master/codebird.js#L745
    function _nonce(length) {
        if (typeof length === "undefined") {
            length = 8;
        }
        if (length < 1) {
            console.warn("Invalid nonce length.");
        }
        var nonce = "";
        for (var i = 0; i < length; i++) {
            var character = Math.floor(Math.random() * 61);
            nonce += "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz".substring(character, character + 1);
        }
        return nonce;
    };