error is in php_self , as its a declared request for server, so its mandatory or its a rule that it should be declared in upper case. so the correct one is
and one more thing, i advice you to mention this code
if(isset($_POST['submit'])) //submit is the name of submit button as declared in your script
because if this code is not mentioned and you are trying to execute two codes in a single page, then undefined index : `variable name` error is shown.
so this is just only my advice !!!