如何每次会话关闭onclick一次？

I wrote this simple code for closing an span after clicking on X, but It loads every time I refresh page or go on another page.

function hinweisClose() {
                var x = document.getElementById("hinweis_header"); {
                        x.style.display = "none";
                }
        }

And this is the code in php:

<div id="hinweis_header">
    <span style="vertical-align: middle; padding-top: 20px; font-weight: bold;"><a href="<?=SHOP_URL_HTTPS?>/<?=$param["links"]["service"]?>/<?=$sprachdatei["links"]["link_hinweis"]?>"><b>Nur heute: 10 % auf alle Jersey Stoffe >><?=$sprachdatei['header']['hinweis_header']?></b></a></span>
    <div class="close-btn" style="position: absolute; display: inline-block; top: -4px; padding-right: 6px; color: #fff;"><span class="rwd-buttinette-icon rwd-icon-remove-circle-1" onclick="hinweisClose()" style="float: right;"></span></div>
</div>

And I've tried with sessionStorage, but can't get it to work:

if (sessionStorage.getItem('HinweisOnce') !== 'true') {
        function hinweisClose() {
                var x = document.getElementById("hinweis_header"); {
                        x.style.display = "none";
                }
        }
    sessionStorage.setItem('HinweisOnce','true');
   }

I want it to load just once until it's closed and stays closed for that session. Can someone help me?

After closing the span add a cookie, for example:

document.cookie = "popup=closed";

Then you can check for the cookie before displaying the span again, for example:

isClosed = document.cookie.replace(/(?:(?:^|.*;\s*)popup\s*\=\s*([^;]*).*$)|^.*$/, "$1") === "closed";
if(isClosed) {
    displayMySpan();
}

You can read more about JS cookies here.

For PHP based solution you can still set the cookie after closing the span, something like:

document.cookie = "popup=closed; path=/";

Then in your PHP code you need something like:

if (isset($_COOKIE['popup']) && $_COOKIE['popup'] === "closed") {
    //code to display div here
};