Problem with array

[Lassie]

I am trying to debug a script that provides a download link from a shopping cart.
The logic is:
1. pass the cart variables and the product id to a function which retrieves the
download file reference from the database.
2.make an array of the results which is returned to a function which prints the link(s) and store them in a variable.
This will be used to copy the file to a pick up folder.

I am printing the links to establish that I have this part working correctly.
The code is:

//call the functions
$dl_link=display_dl_link2($_SESSION['cart'],'product_id');result (links) are returned to $dl_link

display_dl_link($dl_link);//print the links.

function display_dl_link2($cart,$product_id)
{

foreach ($cart as $product_id => $qty){
echo "The value of $product_id is $qty<br />";//de-bug code: This gives values
}
// query database for the relevant file references book

  if (!$product_id || $product_id==''){
    return false;
    }
$connection = db_connect();   
  $query = "select dl_link from products where product_id='$product_id'";
  $result = mysql_query($query);
  if (!$result){
mysql_error();
return false;

  if(mysql_num_rows($result)==0){
  echo "there were no results";

}else {
while ($row = mysql_fetch_assoc($result)){
  echo $row['dl_link'];
$dl_link = $row['dl_link'];

} 
   
$result = db_result_to_array($result);
   
  return $result;
  }
}
}

function db_result_to_array($result)
{
  $res_array = array();

  for ($count=0; $row = mysql_fetch_assoc($result); $count++)
    $res_array[$count] = $row;

  return $res_array;
}
function display_dl_link($dl_link)
{
if (!is_array($dl_link))
  {
    echo 'No dl links currently available<br/>';
    return;

  }
 
foreach ($dl_link as $row)
  {
  $link = $row['dl_link'];
  echo "this is the reference $link";
}
}
What I get is the no array message - No dl links currently available.

Can anyone suggest how I can find out what is going wrong?

[Psycho]

What is the exact error message and what line is throwing the error?

EDIT: Also, please edit your post to put the code within CODE tags.

[sasa]

[code]try to close this if block [if (!$result){
  mysql_error();
  return false;
}[/code]

[Lassie]

Thanks for the help.
I am not getting an error message.
The function display_dl_link2 seems not to return an array back to function display_dl_link.
I have checked that dl_link is populated before the db_results_to array function is called.
How would I check that display_dl_link has been populated?
Thanks for your help.
lassie