Simple Alt Value for Custom Field

Hi there,

So I’m running a loop on a series of custom fields to populate a simple slideshow feature. This is all working fine but the problem I have is that I cannot figure out how to attribute the alt text I have defined when initially uploading images to the media library.

Here’s the code:

<?php $businessimagemain = get_post_meta($post->ID, 'Business image main', false); ?>

  <?php if ( $businessimagemain ) : ?>
    <?php foreach($businessimagemain as $businessimagesmain) {
      $alt_text = get_post_meta($attachment->ID, '_wp_attachment_image_alt', true);
      echo '<img src="'.$businessimagesmain.'" alt="'.$alt_text.'" />';
    } ?>

  <?php else : ?>
    <p>Slideshow currently unavailble.</p>		      

  <?php endif; ?>

Any ideas guys?

Cheers