Variable doesn't work inside JQuery scroll function

my goal is to create and display variable which will record scroll position. While the scroll function seems to be working (for example i can alert a message inside it) but when I add a scroll_pos variable it just stops working. I have followed this tutorial https://www.youtube.com/watch?v=AwgODLLSgwU but i don't understand what's wrong with my code. I use <div id="'status> to display the variable. Any suggestions? Here's the code https://jsfiddle.net/avxgeeah/

$(document).ready(function(){

    $("#text_area").scroll(function(){
            var scroll_pos = $(this).scrollTop();


        alert(scroll_pos);
});

});