function girl(id,url,name){
  this.id = id;
  this.url = url;
  this.name = name;
}

var girlsArray = new Array(
  new girl('kinosakimomo','kinosakimomo.jpg','城崎もも'),
  new girl('sonobemisuzu','sonobemisuzu.jpg','園部みすず'),
  new girl('kurosawachiaki','kurosawachiaki.jpg','黒澤ちあき'),
  new girl('arimuramiyu','arimuramiyu.jpg','有村みゆ'),
  new girl('yamamotoyukari','yamamotoyukari.jpg','山本ゆかり'),

);

function EntranceImg(){
  var randomNumber = Math.floor(Math.random()*girlsArray.length);
  var writeString = new String();
  writeString += '<p class="cover"><img src="../images/cover/' + girlsArray[randomNumber].url + '">';
  document.write(writeString);
}

function CoverImg(){
  var randomNumber = Math.floor(Math.random()*girlsArray.length);
  var writeString = new String();
  writeString += '<p class="cover"><a href="/zaiseki/';
  writeString += girlsArray[randomNumber].id;
  writeString += '/"><img src="images/cover/'+girlsArray[randomNumber].url+'">';
  writeString += '</a></p>';
  document.write(writeString);
}