Help with question #216

So, for question 216 in learning java script, I can not figure out what I’m doing wrong.
It keeps telling me
Type Error: collection[id][prop].push(value); is not a function.
Shouldn’t that be correct syntax?

// Setup
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”
}
};
// Keep a copy of the collection for tests
var collectionCopy = JSON.parse(JSON.stringify(collection));

// Only change code below this line
function updateRecords(id, prop, value) {
if (prop !== “tracks” && value !== “”){
collection[id][prop] = value;
}
if (prop === “tracks” && collection[id] !== “tracks”){
collection[id][prop] = value;
}
if (prop === “tracks” && value !== “”)
{
collection[id][prop].push(value);
}
if (value === “”)
{
delete collection[id][prop];
}
return collection;
}

// Alter values below to test your code
updateRecords(5439, “tracks”, “Take a Chance on Me”);

but am i determining that “tracks” isnt there correctly in my if statement?

How do you create a property as an array?