I have a project that requires a custom block. I'm pretty new to the custom block creation part of concrete5. The project needs the block to be able to choose an image and a PDF file. These are 2 separate fields. An excerpt of the code is as follows:

<?php
$includeAssetLibrary = true;
$assetLibraryPassThru = array(
'type' => 'image'
);
$al = Loader::helper('concrete/asset_library');
$bf=0;
$of=0;

if($controller->getFileID("image")>0){
$bf=$controller->getFileObject("image");
}

if($controller->getFileID("document")>0){
$of=$controller->getFileObject("document");
}
?>


<div class="ccm-block-field-group">
<h2><?php echo t('Image')?></h2>
<?php echo $al->image('ccm-b-image', 'imageID', t('Choose Image'), $bf);?>
</div>

<div class="ccm-block-field-group">
<h2><?php echo t(' Members CV')?></h2>
<?php
echo $al->file('ccm-b-document', 'cvID', t('Choose CV'), $of);
?>
</div>

In both the edit and add php files if you dare to select a PDF or image file in the second field concrete5 produces an error popup that makes absolutely no sense. In fact the popup contains the homepage stripped of any HTML tags! I've even compared what I've done to the image block and there appears to be no real difference except I'm using $al->file instead of $al->image for the second field.

I'm getting really frustrated and the project deadline is rapidly approaching. Does anyone know what I'm doing wrong?

Thanks in advance for any help.