Why does the function only work on the second click?

Question

JavaScript

Why does the function only work on the second click? With one click, nothing happens. This happens when you reload the page.

function openbox(id){
    display = document.getElementById(id).style.display;

    if(display=='none'){
       document.getElementById(id).style.display='block';
    }else{
       document.getElementById(id).style.display='none';
    }
}

<div class="ac" onclick="openbox('box'); return false"><?php profile_picture_show(); ?></div>

Answer 1

Because you're reading the value through style.display and it's coming from the style attribute. For the first time, nothing was written in it. You here - https://learn.javascript.ru/styles-and-classes#th...