How to get catalog name at all levels in magento

Question

I want to display all catalog names from all the levels and I am using the following code and it shows the category at level 1 and I want a nested menu to be displayed

the following is the code snippet

<select id="<?php echo $categorySearchHelper->getCategoryParamName() ?>" name="<?php echo $categorySearchHelper->getCategoryParamName() ?>">
    <option value=""><?php echo $this->__('All') ?></option>
    <?php foreach ($this->getSearchableCategories() as $mainCategory): ?>
        <option value="<?php echo $mainCategory->getEntityId()?>"><?php echo $mainCategory->getName() ?></option>
        <?php if ($categorySearchHelper->showSubCategories()) : ?>
            <?php foreach ($this->getSearchableSubCategories($mainCategory) as $category) : ?>
                <option value="<?php echo $category->getEntityId()?>"><?php echo $categorySearchHelper->getIndentationText() . $category->getName()?></option>
            <?php endforeach;?>
        <?php endif ?>
    <?php endforeach;?>
</select>

Please help

Answer 1

<?php $_helper = Mage::helper('catalog/category') ?>
    <?php $_categories = $_helper->getStoreCategories() ?>
    <?php if (count($_categories) > 0): ?>
            <ul>
                <?php foreach($_categories as $_category): ?>
                    <li>
                        <a href="<?php echo $_helper->getCategoryUrl($_category) ?>">
                            <?php echo $_category->getName() ?><?php $_category = Mage::getModel('catalog/category')->load($_category->getId()) ?>
                            <?php $_subcategories = $_category->getChildrenCategories() ?>
                            <?php if (count($_subcategories) > 0): ?>
                                <ul>
                                <?php foreach($_subcategories as $_subcategory): ?>
                                    <li>
                                        <a href="<?php echo $_helper->getCategoryUrl($_subcategory) ?>">
                                        <?php echo $_subcategory->getName() ?>
                                    </a>
                                    </li>
                                <?php endforeach; ?>
                                </ul>
                            <?php endif; ?>
                        </a>
                    </li>
                <?php endforeach; ?>
            </ul>
    <?php endif; ?>