What is wrong with this code snippet??

I use this code in order to get custom field values (image urls):

<?php
} ?>
<?php $withdraws=get_post_meta($post->ID,"tcwithdraws",false); ?>

<?php foreach($tcwithdraws as $withdraw)
{
list($width, $height, $type, $attr) = getimagesize($withdraw);
?>
<img src="<?php echo $withdraw;?>" <?php echo $attr; ?> alt="">
<? } ?>

The custom key I have created is named “tcwithdraws“. The value is image urls. But I get told that I have an un-defined variable?? Could anyone please point it out from this code??