Notice: Undefined index: product_id  in /home/masinidecusut/public_html/app/code/local/Webkul/Preorder/controllers/IndexController.php on line 7

#0 /home/masinidecusut/public_html/app/code/local/Webkul/Preorder/controllers/IndexController.php(7): mageCoreErrorHandler(8, 'Undefined index...', '/home/masinidec...', 7, Array)
#1 /home/masinidecusut/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Webkul_Preorder_IndexController->indexAction()
#2 /home/masinidecusut/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('index')
#3 /home/masinidecusut/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/masinidecusut/public_html/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#5 /home/masinidecusut/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#6 /home/masinidecusut/public_html/index.php(92): Mage::run('', 'store')
#7 {main}