[Add_Pdf.php Error]

I am getting the same error complaining about  index. Kindly assist.

 

Array

(

    [0] => Array

        (

            [file] => C:\wamp\www\newstore\add_pdf.php

            [line] => 81

            [function] => my_error_handler

            [args] => Array

                (

                    [0] => 8

                    [1] => Undefined index: pdf

                    [2] => C:\wamp\www\newstore\add_pdf.php

                    [3] => 81

                    [4] => Array

                        (

                            [GLOBALS] => Array

*RECURSION*

                            [php_errormsg] => POST Content-Length of 182070 bytes exceeds the limit of 25 bytes

                            [_POST] => Array

                                (

                                )



                            [_GET] => Array

                                (

                                )



                            [_COOKIE] => Array

                                (