Magento 1.9 Custom Module Image Upload - php

Question

I would like some help uploading two images in my module
my controller looks like this:
if(isset($_FILES['filename']['name']) && $_FILES['filename']['name'] != '') {
try {
$uploader = new Varien_File_Uploader('filename');
$uploader->setAllowedExtensions(array('jpg','jpeg','gif','png'));
$uploader->setAllowRenameFiles(false);
$uploader->setFilesDispersion(false);
$path = Mage::getBaseDir('media') . DS ;
$uploader->save($path, $_FILES['filename']['name'] );
} catch (Exception $e) {
}
$data['filename'] = $_FILES['filename']['name'];
}
if(isset($_FILES['filename_mobile']['name']) && $_FILES['filename_mobile']['name'] != '') {
try {
$uploader = new Varien_File_Uploader('filename_mobile');
$uploader->setAllowedExtensions(array('jpg','jpeg','gif','png'));
$uploader->setAllowRenameFiles(false);
$uploader->setFilesDispersion(false);
$path = Mage::getBaseDir('media').DS.'mobile'.DS;
$uploader->save($path, $_FILES['filename_mobile']['name'] );
} catch (Exception $e) {
}
$data['filename_mobile'] = $_FILES['filename_mobile']['name'];
}
and my form is like this:
$fieldset->addField('filename', 'image', array(
'label' => Mage::helper('configuracao')->__('Banner Desktop'),
'required' => false,
'name' => 'filename',
));
$fieldset->addField('filename_mobile', 'image', array(
'label' => Mage::helper('configuracao')->__('Banner Mobile'),
'required' => false,
'name' => 'filename_mobile',
));
when I save, the database is "Array" and the thumbnail also says "Array"
where am i wrong could someone please help me?