Ошибкпи как исправитьNotice: Undefined variable: bookи  Warning: Invalid argument supplied for foreach()


<table width="100%">
    <?php foreach ($book as $entry) { extract($entry, EXTR_OVERWRITE)?>
        <tr>
            <td>Имя: <?=$name?></td> <!-- вместо $entry['name'] -->
            <td>Адрес: <?=$url?></td> <!-- вместо $entry['url'] -->
        </tr>
        <tr><td colspan="3"><?=$text?></td></tr>
        <tr><td colspan="3"><hr /></td></tr>
    <? } ?>
</table>

! ) Notice: Undefined variable: book in /var/www/php.xxx/1/funcarr/sort1.php on line 2
Call Stack
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Time
Memory
Function
Location
1
0.0005
393520
{main}( )
.../sort1.php:0

( ! ) Warning: Invalid argument supplied for foreach() in /var/www/php.xxx/1/funcarr/sort1.php on line 2
Call Stack
#
Time
Memory
Function
Location
1
0.0005
393520
{main}( )
.../sort1.php:0