Magento undefined variable: isCustomerLogged error

Question

I'm getting this error in my logs, how can I solve this? Here is error and the file it relates to. This is line 15:

<?php if (!$isCustomerLogged): ?>

ERR (3): Notice: Undefined variable: isCustomerLogged in /domains/dev.domain.co.uk/http/app/design/frontend/base/default/template/detailedreview/wrapper.phtml on line 15

<?php if (!$isCustomerLogged): ?>
    <div class="login-dialog-block" style="display: none;">
        <div class="login-dialog-container">
            <?php echo $this->getChildHtml('customer_form_login');?>
            <?php echo $this->getChildHtml('customer_form_register');?>
        </div>
        <div class="clearer"></div>
    </div>
<?php endif;?>

Answer 1

Replace if (!$isCustomerLogged): with below code

if(!Mage::getSingleton('customer/session')->isLoggedIn()):

Answer 2

Try this one:

<?php $customerIsLoggedIn = Mage::getSingleton('customer/session')->isLoggedIn(); ?> //return if customer is logged in

<?php if (!$customerIsLoggedIn): ?> //here we hide the code bellow if customer is not logged in
    <div class="login-dialog-block" style="display: none;">
        <div class="login-dialog-container">
            <?php echo $this->getChildHtml('customer_form_login');?>
            <?php echo $this->getChildHtml('customer_form_register');?>
        </div>
        <div class="clearer"></div>
    </div>
<?php endif;?>

Answer 3

I have faced same problem in Magento like undefined variables in all pages. Go to Index.php search below code & replaced.

if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) {
   Mage::setIsDeveloperMode(true);
}


to 

if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) {
   Mage::setIsDeveloperMode(false);
}