I need help with the following error:

Fatal error: Call to a member function getno_cart_button() on a non-object in /var/home/hifi-studio_at/www/app/design/frontend/default/theme582/template/catalog/product/compare/list.phtml on line 134

This error occurs only in the compare-list. I made an Attribute called "no_cart_button", if it is checked, the product does not show the "Cart-Button" any more, but instead a "Anfrage (Ask)" linking to a Contact-Page. On all other lists and grids it does work. But why no here? This is the code I used:

<!-- // Warenkorb in Anfrage verändern // Start // -->
                <?php   if($_product->getno_cart_button()){ ?> <div class="add-to-cart"><button type="button" title="<?php echo $this->__('Anfrage') ?>" class="button btn-cart" onClick="parent.location='/kontakt'"><span><span><?php echo $this->__('Anfrage') ?></span></span></button></div> <?php }
                                        else { ?> <p><button type="button" title="<?php echo Mage::helper('core')->quoteEscape($this->__('Add to Cart')) ?>" class="button btn-cart" onclick="setPLocation('<?php echo $this->helper('catalog/product_compare')->getAddToCartUrl($_item) ?>', true)"><span><span><?php echo $this->__('Add to Cart') ?></span></span></button></p> <?php } ?>
                <?php else: ?>
                <!-- // Warenkorb in Anfrage verändern // ENDE // -->

This Error also occurs only with Products that have this attribute. Others don't show the cart button nor the error.

Any suggestions? Thanks!

This is the full code:

<?php

/**

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• that is bundled with this package in the file LICENSE_AFL.txt.
• It is also available through the world-wide-web at this URL:
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• Do not edit or add to this file if you wish to upgrade Magento to newer
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• needs please refer to http://www.magento.com for more information.
• @category design
• @package rwd_default
• @copyright Copyright (c) 2006-2015 X.commerce, Inc. (http://www.magento.com)
• @license http://opensource.org/licenses/afl-3.0.php Academic Free License (AFL 3.0) / / @var $this Mage_Catalog_Block_Product_Compare_List */ ?>

__('Compare Products') ?>

__('Print This Page') ?> getItems()->count() ?> getItems() as $_item): ?> %" /> 2): ?> getItems() as $_item): ?>   helper('catalog/product_compare')->getRemoveUrl($_item) ?>');" title="quoteEscape($this->__('Remove This Item')) ?>">__('Remove This Item') ?> getItems() as $_item): ?>   getProductUrl($_item) ?>', true)" title="stripTags($_item->getName(), null, true) ?>">helper('catalog/image')->init($_item, 'small_image')->resize(125, 125); ?>" width="125" height="125" alt="stripTags($_item->getName(), null, true) ?>" /> getProductUrl($_item) ?>', true)" title="stripTags($_item->getName(), null, true) ?>">helper('catalog/output')->productAttribute($_item, $_item->getName(), 'name') ?> getReviewsSummaryHtml($_item, 'short') ?> getPriceHtml($_item, true, '-compare-list-top') ?> getItems() as $_item): ?>   isSaleable()): ?> getno_cart_button()){ ?>

__('Anfrage') ?>" class="button btn-cart" onClick="parent.location='/kontakt'">__('Anfrage') ?>

__('Add to Cart') ?>" class="button btn-cart" onclick="setLocation('getAddToCartUrl($_product) ?>')">__('Add to Cart') ?> __('Out of stock') ?>

helper('wishlist')->isAllow()) : ?>

getAddToWishlistUrl($_item) ?>" class="link-wishlist">__('Add to Wishlist') ?>

getAttributes() as $_attribute): ?> getItems() as $_item): ?> getStoreLabel() ?> getAttributeCode()) { case "price": ?> getPriceHtml($_item, true, '-compare-list-' . $_attribute->getCode()) ?> helper('catalog/image')->init($_item, 'small_image')->resize(125, 125); ?>" width="125" height="125" alt="escapeHtml($_item->getName()) ?>" title="escapeHtml($_item->getName()) ?>" /> getProductAttributeValue($_item, $_attribute),0,10); break; default: ?> helper('catalog/output')->productAttribute($_item, $this->getProductAttributeValue($_item, $_attribute), $_attribute->getAttributeCode()) ?> getItems() as $_item): ?>   getPriceHtml($_item, true, '-compare-list-bottom') ?> getno_cart_button()){ ?>

__('Anfrage') ?>" class="button btn-cart" onClick="parent.location='/kontakt'">__('Anfrage') ?>

__('Add to Cart') ?>" class="button btn-cart" onclick="setLocation('getAddToCartUrl($_product) ?>')">__('Add to Cart') ?> __('Out of stock') ?>

helper('wishlist')->isAllow()) : ?>

getAddToWishlistUrl($_item);?>" class="link-wishlist">__('Add to Wishlist') ?>

quoteEscape($this->__('Close Window')) ?>" class="button" onclick="window.close();">__('Close Window') ?> getSkinUrl('images/opc-ajax-loader.gif') ?>" alt="quoteEscape($this->__('Please wait...')) ?>" title="quoteEscape($this->__('Please wait...')) ?>" class="v-middle" /> __('Please wait...') ?> decorateTable('product_comparison');

    /**
     * Send remove item request, after that reload windows
     */
    function removeItem(url)
    {
        new Ajax.Request(url, {
            parameters: {isAjax: 1, method: 'POST'},
            onLoading: function(){$('compare-list-please-wait').show();},
            onSuccess: function(transport) {
                $('compare-list-please-wait').hide();
                window.location.reload();
                window.opener.location.reload();
            }
        });
    }
</script>

<script type="text/javascript">window.close();</script>