jquery - Undefined index: posts_start on one localhost machine, but not on another? with Laravel 4 -

i have been trying set "load-more" functional widget, , successful earlier today on localhost. however, on computer (same mac os, mamp, etc...), getting error session variable: undefined index: posts_start.

in javascript, these relevant lines:

<?php $number_of_posts = 2; ?>; //<?php $_session['posts_start'] = $_session['posts_start'] ? $_session['posts_start'] : $number_of_posts; ?>; <?php $_session['posts_start'] = 2 ?>;  var start = <?php echo $_session['posts_start']; ?>; 

this using laravel 4, have session running current user (no need use session_start()). not sure why isn't working on machine, working on another. thoughts? thank you.

i use laravel's session library. lib can handle situations beautifly...

var start = <?=session::get('posts_start', 2) ?>;  // or this, if use blade syntax var start = {{ session::get('posts_start', 2) }}; 

what call do? tries posts_start session, , fallbacks number 2, if number not set in session.