Only retrieving last option in multiple select element - laravel

Question

The form is posted and I'm retrieving the inputs with:
$inputs = Input::all();
return Response::json($inputs);
The form is like this:
<form role="form" method="POST" action="/account/enrollments/{{ $activity->id }}/update" class="form-horizontal" autocomplete="off">
<input type="hidden" name="_token" value="{{ csrf_token() }}">
<div class="row">
<div class="col-xs-12 col-md-4">
<h4>Available Students</h4>
<select multiple class="form-control" name="available">
#foreach ($available as $student)
<option value="{{ $student->id }}">{{ $student->firstname }} {{ $student->lastname }}</option>
#endforeach
</select>
</div>
<div class="col-xs-12 col-md-4 push-top">
<button name="enrol" class="btn btn-block btn-effect-ripple btn-primary">Enrol Student(s)</button>
<button name="unenrol" class="btn btn-block btn-effect-ripple btn-warning">Remove Student(s)</button>
</div>
<div class="col-xs-12 col-md-4">
<h4>Currently Enrolled Students</h4>
<select multiple class="form-control" name="enrolled">
#foreach ($enrolled as $student)
<option value="{{ $student->id}}">{{ $student->firstname }} {{ $student->lastname }}</option>
#endforeach
</select>
</div>
</div>
</form>
But the response only shows the id of the last one selected. So, if I select three from the available select, it only returns the id of the last one, like this:
{
"_token": "KOqUu3m0uxwNxPC1BVisFT2y6P86z3uoBqZiEgTa",
"available": "5",
"enrol": ""
}
How do I retrieve all three inputs?
Here's the actual HTML from source:
<form role="form" method="POST" action="/account/enrollments/1/update" class="form-horizontal" autocomplete="off">
<input type="hidden" name="_token" value="KOqUu3m0uxwNxPC1BVisFT2y6P86z3uoBqZiEgTa">
<div class="row">
<div class="col-xs-12 col-md-4">
<h4>Available Students</h4>
<select multiple class="form-control" name="available">
<option value="2">Student 2</option>
<option value="4">Student 4</option>
<option value="5">Student 5</option>
</select>
</div>
<div class="col-xs-12 col-md-4 push-top">
<button name="enrol" class="btn btn-block btn-effect-ripple btn-primary">Enrol Student(s)</button>
<button name="unenrol" class="btn btn-block btn-effect-ripple btn-warning">Remove Student(s)</button>
</div>
<div class="col-xs-12 col-md-4">
<h4>Currently Enrolled Students</h4>
<select multiple class="form-control" name="enrolled">
<option value="3">Student 3</option>
</select>
</div>
</div>
</form>

Answer 1

It seems that you have to put[] in the name value:
name="available[]"
Then it returns an array.