I got a JSON name collection like this:

```
[{

   "name":"Jim",
   "prize":"Nokia Mobile"
  },
  {

   "name":"Marry",
   "prize":"iPhone"
  },
  {

   "name":"Alice",
   "prize":"iPad"
  }

]

```

now I'd like to filter this JSON by a string: var data= "m";

so, this is what I've done:

```
    var data= "m";

    collection = _.filter(collection,function(c){

        return _.any(c,function(k){

            return k.name.toLowerCase().indexOf(data.toLowerCase()) != -1;

        });

    });

```

so, in this case, collection return elements which has m in their name.

However, I've got "Cannot call method 'toLowerCase' of undefined".

I tried to put an alert "alert(c.name);" before the last return, and it's return "undefined". It shouldn't be, isn't it?

what need I change to fix this?