js检测cookie是否存在

检测是否存在lastUserID的cookie

function cookie(){
   var cookieArray=document.cookie.split("; ");
       var cookie=new Object();
     for (var i=0;i<cookieArray.length;i++){
      var arr=cookieArray[i].split("=");
      if(arr[0]=='lastUserID')return unescape(arr[1]);
   }
   return "";
}