PHP에서 체크박스의 값을 얻는 방법

<form id="form1" name="form1" method="post" action="checkbox.php">
<input type=checkbox name=checkbox[] value="1">
<input type=checkbox name=checkbox[] value="2">
<input type=checkbox name=checkbox[] value="3">
<input type=checkbox name=checkbox[] value="4">
<input type=checkbox name=checkbox[] value="5">
<input type="submit" name="button" id="checkbox" value="提交" />
</form>

<?php
$text1=$_POST[&#39;checkbox&#39;];
for($i=0;$i<count($text1);$i++)
{
$yourwant = $text1[$i]; 
echo $yourwant."<br/>";
}
?>