Invalid form key

#0 /home/advance1/public_html/app/code/core/Mage/Checkout/controllers/CartController.php(636): Mage::throwException('Invalid form ke...')
#1 /home/advance1/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Checkout_CartController->ajaxDeleteAction()
#2 /home/advance1/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('ajaxDelete')
#3 /home/advance1/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#4 /home/advance1/public_html/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#5 /home/advance1/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#6 /home/advance1/public_html/index.php(85): Mage::run('', 'store')
#7 {main}