Where exactly to add the code in form_detail.php?

Hi there

I would like to add my own list to the Predefined Choices field; unfortunately this is not something built in to Gforms but I hope you will make that an option soon. In the meantime, I am a novice at PHP.

I did find the solution in this post: http://www.gravityhelp.com/forums/topic/using-the-gform-predefined-choices-filter

but I don't know where EXACTLY in the form_detail.php I need to paste this code:

<?php

add_filter("gform_predefined_choices", "add_predefined_choice");
function add_predefined_choice($choices){
   $choices["My New Choice"] = array("Choice 1", "Choice 2", "Choice 3");
   return $choices;
}
?>

I do understand I need to add my own title and array/choices into the code before inserting it; but just where to PASTE the code into the form_detail.php so I don't break the plugin??

thanks!!

THANK YOU, Kevin!!