Remove assign category from product

/*-----------Remove product From assign category Start------------- */
$productId=5;
$product=Mage::getModel("catalog/product")->load($productId);
$productIdss=$product->getId();
$all_cats = $product->getCategoryIds($productIdss);
  foreach($all_cats as $_catId)
{
$product=Mage::getSingleton('catalog/category_api')->removeProduct($_catId,$productIdss);
}
/*-----------Remove product From assign category End------------- */

Magento programmatically remove product images

/* Remove Product media Image Start*/
$ptoductId=120;
$productImgRemov= Mage::getModel('catalog/product')->load($ptoductId);
$entityTypeId = Mage::getModel('eav/entity')->setType('catalog_product')->getTypeId();
$mediaGalleryAttribute = Mage::getModel('catalog/resource_eav_attribute')->loadByCode($entityTypeId, 'media_gallery');
$gallery = $productImgRemov->getMediaGalleryImages();
foreach ($gallery as $image)
$mediaGalleryAttribute->getBackend()->removeImage($productImgRemov, $image->getFile());
$productImgRemov->save();
/* Remove Product media Image End*/

get category in tree view in magento

<?php include "app/Mage.php";
    Mage::app();
$STORE_ID=5
$root_categories_id=Mage::app()->getStore($STORE_ID)->getRootCategoryId();
//$cat_mod = Mage::getModel('catalog/category')->setStoreId(STORE_ID)->load($root_category_id);
//$main_categories=Mage::getModel('catalog/category')->getCategories($root_category_id);



function getCategoryList($cateid){

$main_categories = Mage::getModel('catalog/category')->getCategories($cateid);

foreach($main_categories as $_cate)
{

$categories = Mage::getModel('catalog/category')->load($_cate->getId());
/*echo "<pre>";
print_r($categories);
echo "</pre>";*/
if ($categories->getIsActive())
{

echo "<li value='".$categories->getId()."'>";
for($m=1;$m<=substr_count($categories->path,'/');$m++){
echo "&nbsp"."&nbsp";
}?>
<a href="manage-category.php?Id=<?php echo $categories->getId(); ?>">
<?php
echo $categories->getName()."</a></li>";

$selected='';

//echo '<option value="'. $_category->getId().'" '.$selected.' >'. $space . $_category->getname().'</option>';

$children = $categories->getChildren();

if(count($children)>0)
{
getCategoryList($categories->getId());
}

}
}
}
?>


<div class="category-product">
<div id="narrow-by-list">
<p class="cate-name"><?php echo 'Category' ?> : <?php echo $cat_mod->getName() ?></p>
</div>

<ul id="treemenu1" class="treeview">
<?php getCategoryList($root_categories_id); ?>
</ul>
</div>

check user login or not in magento

Not: unauthorized user Redirect to login page with "$beforAutoUrl " URL and after login redirect to "$beforAutoUrl" url
====================================
if( !Mage::getSingleton( 'customer/session' )->isLoggedIn() ){
$session = Mage::getSingleton('customer/session');
$beforAutoUrl = Mage::getBaseUrl('web').str_replace('/clients/omegabanners/','',$_SERVER['REQUEST_URI']);
$beforAutoUrl="";
$session->setBeforeAuthUrl($beforAutoUrl);

Mage::app()->getResponse()->setRedirect(Mage::getUrl("customer/account/login"));
}else{

echo "User Loged In"
}

magento user login information

$session=Mage::getSingleton('customer/session', array('name'=>'frontend'));
$userId=$session->getId();