function loadTwitter(){
  $.ajax({
    url : "http://twitter.com/statuses/user_timeline/kei_shimada.json",
    dataType : "jsonp",
    data : {
      count:1
    },
    jsonp : "callback",
    success : function(json){
      showTwitter(json);
    },
    error : function(){
      $('#twitter > #twitter_msg').text("error");
    }
  });
}


function showTwitter(json){
  $('#twitter > #twitter_msg')
    .text(json[0].text);
  $('#twitter > #twitter_date').append(
    $('<a/>')
      .text(DateString(json[0].created_at)+', Follow Kei on Twitter')
      .attr('href','http://twitter.com/kei_shimada')
      .attr('target','_blank')
  );
}

function digit (num) {
    if (num < 10) {num = ' ' + num;}
    return num;
}

function DateString (getEntryDate){
  var currentDate = new Date();
  var time = getEntryDate.split(" ");
  var post_date = time[1] + " "
                + time[2] + ", "
                + time[5] + " "
                + time[3];
  var entryDate = new Date(post_date);
  var elapsedTime = (currentDate.getTime() + currentDate.getTimezoneOffset()*60*1000 - entryDate.getTime())/1000;
  elapsedTime = Math.ceil(elapsedTime);
  var message = null;
  if (elapsedTime < 60) {
    message =  'just now';
  } else if (elapsedTime < 120) {
    message =  '1 minute ago';
  } else if (elapsedTime < (60*60)) {
    message =  digit(Math.floor(elapsedTime / 60)) + ' minutes ago';
  } else if (elapsedTime < (120*60)) {
    message =  '1 hour ago';
  } else if (elapsedTime < (24*60*60)) {
    message =  digit(Math.floor(elapsedTime / 3600)) + ' hours ago';
  } else if (elapsedTime < (7*24*60*60)) {
    message =  digit(Math.floor(elapsedTime / 86400)) + ' days ago';
  } else {
    message =  digit(Math.floor(elapsedTime / 604800)) + ' weeks ago';
  }
  return message;
}