function dateFormat(d,f) {
  var str = '', i, s;
  for(i = 0; i < f.length; ++i) {
    switch(f[i]) {
    case 'Y' : s = d.getUTCFullYear(); break;
    case 'y' : s = (d.getUTCFullYear() + '').substr(2); break;
    case 'F' : s = monthsLong[d.getUTCMonth()]; break;
    case 'M' : s = monthsShort[d.getUTCMonth()]; break;
    case 'm' : s = ('0' + (d.getUTCMonth() + 1)).substr(-2); break;
    case 'n' : s = d.getUTCMonth() + 1; break;
    case 'd' : s = ('0' + d.getUTCDate()).substr(-2); break;
    case 'D' : s = daysShort[d.getUTCDay()]; break;
    case 'l' : s = daysLong[d.getUTCDay()]; break;
    case 'a' : s = ['am','pm'][d.getUTCHours() > 11 ? 1 : 0]; break;
    case 'A' : s = ['AM','PM'][d.getUTCHours() > 11 ? 1 : 0]; break;
    case 'g' : s = d.getUTCHours() % 12 || 12; break;
    case 'G' : s = d.getUTCHours(); break;
    case 'h' : s = ('0' + (d.getUTCHours() % 12 || 12)).substr(-2); break;
    case 'H' : s = ('0' + d.getUTCHours()).substr(-2); break;
    case 'i' : s = ('0' + d.getUTCMinutes()).substr(-2); break;
    case 's' : s = ('0' + d.getUTCSeconds()).substr(-2); break;
    default:
      s = f[i];
    }
    str += s;
  }
  return str;
}
