simple function for parser a URL's querystring into an object of key-value pairs

parse-querystng.js

function parse(qs) {
  return qs.replace(/^\?/, '').split('&').reduce(function(col, pairStr) {
    // pairStr is of form `foo=bar`
    var pair = pairStr.split('=').map(decodeURIComponent);
    col[pair[0]] = pair[1];
    return col;
  }, {});
}