Generate a UUID... use node-uuid if you can though.

uuidGen.js

function uuidGen() {
  var uuid = 'xxxxxxxxxxxxyxxxyxxxxxxxxxxxxxxx'.replace(/[xy]/g,
    function(c) {
      var r = Math.random() * 16 | 0,
      v = c == 'x' ? r : (r & 0x3 | 0x8);
      return v.toString(16);
    });
  return uuid;
}