commenting module by ajax not working in laravel 5 - ajax

Question

i am working on commenting module in my project by ajax. i am getting this error
POST http://127.0.0.1:8000/comments 500 (Internal Server Error)
and the data not post. what i am doing wrong? My route is a resource route and i want to display it without refreshing the page .
Form
<form action="{{route('comments.store')}}" method="post">
{{ csrf_field() }}
<div class="col-md-11 col-sm-11">
<div class="form-group">
<textarea name="comment-msg" id="comment-name" cols="30" rows="1" class="form-control" placeholder="comment here..."></textarea>
<input type="hidden" id="eventID" name="eventID" value="<?php echo $eventData->id; ?>">
<input type="hidden" id="userID" name="userID" value="<?php echo Auth::user()->id; ?>">
</div>
</div>
<div class="col-md-12">
<button type="submit" id="submit-comment" class="btn-primary pull-right">Comment</button>
</div>
</form>
Ajax Call
<script>
$.ajaxSetup({
headers: {'X-CSRF-Token': $('meta[name=_token]').attr('content')}
});
$( '#submit-comment' ).click(function() {
var formData = {
'message' : $('#comment-msg').val(),
'eventID' : $('#eventID').val(),
'userID' : $('#userID').val(),
};
$.ajax({
type : 'POST',
url : '{{route('comments.store')}}',
data : formData,
dataType : 'json',
encode : true,
success: function (response) {
console.log(response);
},
error: function(xhr, textStatus, thrownError) {
alert('Something went to wrong.Please Try again later...');
}
});
event.preventDefault();
} );
</script>
Controller
public function store(Request $request)
{
$content = $request->input( 'comment-msg' );
$userID = $request->input( 'userID' );
$eventID = $request->input( 'eventID' );
$response=Comment::create([
'user_id' => $userID,
'event_id' => $eventID,
'message' => $content,
]);
return response()->json($response);
}
Route
Route::resource('comments', 'CommentsController');