Magento : Set Meta Title Automatically Save After Product

Here I would just like to save the meta tilte field automatically with similar to produuct name If I save click on the Save or Save and continue edit button in magento admin.for This I will create a Observer through which I can Update the meta_title attribute and save in data base so that If I create a product then meta title filed will be filled up automatically by help of product name .For that I will be using an magento events catalog_product_save_after.The event which called after save of catalog product So please check the below code for reference :


For doing above things I mainly need two things :
1)config.xml file through which I can I can create an event and call to observer
2)observer.php file thorugh which I can do my coding part.
MyNamespace = LR
MyMoodulename = Metatitle
config.xml :
app\code\local\LR\Metatitle\etc\config.xml


Observer.php : app\code\local\LR\Metatitle\Model\ Observer.php