无法抓取indexOf-不是函数

我有一个数组,我想存储名称和一段信息,这样我就可以调用该项来检索信息。当我尝试搜索数组以首先检查时,项目位于我收到的数组中: GenreArray.indexOf is not a function

var GenreArray = {"00's":"Includes Amy Whinehouse, Westlife, The Killers...","90's":"Includes Britney Spears, Backstreet Boys, Mariah Carey..."};

if(GenreArray.indexOf("00's") > -1) //Crashed here
{
 //Code here
  console.log(GenreArray["00's"]);
}