Sorting mutidimensional array

<?php

	// function cmp( $a , $b )
	// {
	// 	if( $a == $b )
	// 	{
	// 		return 0;
	// 	}

	// 	return ($a > $b) ? 1 : -1;
	// }

	function name_sort( $x , $y )
	{
		return strcmp($x['name'], $y['name']);
	}

	function grade_sort($x , $y )
	{
		return $x['grade'] <
		 $y['grade'];
	}

	$students = array (

		256 => array ('name' => 'Jon', 'grade' => 98.5),
		2 => array ('name' => 'Vance', 'grade' => 85.1),
		9 => array ('name' => 'Stephen', 'grade' => 94.0),
		364 => array ('name' => 'Steve', 'grade' => 85.1),
		68 => array ('name' => 'Rob', 'grade' => 85.1)

		);


	echo '<h3>Array As is</h3><pre>' . print_r($students , 1) . '</pre>';

	uasort($students, 'name_sort');

	echo '<h3>Array Sorted By Name</h3><pre>' . print_r($students , 1) . '</pre>';

	uasort($students, 'grade_sort');

	echo '<h3>Array sorted by grade</h3><pre>' . print_r($students , 1) . '</pre>';




 ?>