var collection = {
   2548: {
     album: "Slippery When Wet",
     artist: "Bon Jovi",
     tracks: [
       "Let It Rock",
       "You Give Love a Bad Name"
     ]
   },
   2468: {
     album: "1999",
     artist: "Prince",
     tracks: [
       "1999",
       "Little Red Corvette"
     ]
   },
   1245: {
     artist: "Robert Palmer",
     tracks: [ ]
   },
   5439: {
     album: "ABBA Gold"
   }
};

function updateRecords(id, prop, value) {

   var check = collection[id].hasOwnProperty("tracks");

   switch (prop) {
      case "album":
         collection[id][prop] = value;
         break;
      case "artist":
         if (value == "") {
            delete collection[id][prop];
         } else {
            collection[id][prop] = value;
         }
         break;
      case "tracks":
         if (value == "") {
            delete collection[id][prop];
         } else if (check == true) {
            collection[id][prop].push(value);
         } else {
            collection[id][prop] = [value];
         }
         break;
   }

   console.log(collection);
}