In PHP you can use isset method when you want to get All data through form. It is better way to get all data through form. There are anotrher Global Method of PHP that is "$_SERVER["PHP_SELF"]" . You can also use this on.
Note: If you dont used isset method and get all data through the form then there is occure error " Notice: Undefined index: nm in C:xampphtdocsdemocheck.php on line 2" so try to use isset metho"