Change the arrow icon Fullwidth Slider

Hi there,

I would like to change the arrow icons within the Fullwidth Slider via jQuery with another icon (fontello).

But whatever i do, it keeps saying: Uncaught TypeError: $ is not a function.
I added a custom js in the childtheme with:

function add_customjs() {
   wp_enqueue_script( 'customjs', get_stylesheet_directory_uri().'/js/custom.js', array('jquery'), 2, true );
}
add_action( 'wp_enqueue_scripts', 'add_customjs', 100 );

I added <script> tag in the google tracking field..

<script>
$(window).load(function(){
	$('#next').data('av_icon', '');
	$('#next').data('av_iconfont', 'fontello');
});
</script>

Both failed…

Any other ideas?