I wanted to use the HTML code from the page → https://www.w3schools.com/howto/howto_js_lightbox.asp
After saving the page, I get an error message. Why, how to fix it?
PrestaShop saves the code like this:
<!-- Images used to open the lightbox --> <div class="row"> <div class="column"><img src="/img/cms/projekty/projekt.jpg" onclick="openModal();currentSlide(1)" class="hover-shadow" /></div> <div class="column"><img src="/img/cms/projekty/projekt.jpg" onclick="openModal();currentSlide(2)" class="hover-shadow" /></div> <div class="column"><img src="/img/cms/projekty/projekt.jpg" onclick="openModal();currentSlide(3)" class="hover-shadow" /></div> <div class="column"><img src="/img/cms/projekty/projekt.jpg" onclick="openModal();currentSlide(4)" class="hover-shadow" /></div> </div> <!-- The Modal/Lightbox --> <div id="myModal" class="modal"><span class="close cursor" onclick="closeModal()">×</span> <div class="modal-content"> <div class="mySlides"> <div class="numbertext">1 / 4</div> <img src="/img/cms/projekty/projekt.jpg" style="width: 100%;" /></div> <div class="mySlides"> <div class="numbertext">2 / 4</div> <img src="/img/cms/projekty/projekt.jpg" style="width: 100%;" /></div> <div class="mySlides"> <div class="numbertext">3 / 4</div> <img src="/img/cms/projekty/projekt.jpg" style="width: 100%;" /></div> <div class="mySlides"> <div class="numbertext">4 / 4</div> <img src="/img/cms/projekty/projekt.jpg" style="width: 100%;" /></div> <!-- Next/previous controls --> <a class="prev" onclick="plusSlides(-1)">❮</a> <a class="next" onclick="plusSlides(1)">❯</a> <!-- Caption text --> <div class="caption-container"></div> <!-- Thumbnail image controls --> <div class="column"><img class="demo" src="/img/cms/projekty/projekt.jpg" onclick="currentSlide(1)" alt="Nature" /></div> <div class="column"><img class="demo" src="/img/cms/projekty/projekt.jpg" onclick="currentSlide(2)" alt="Snow" /></div> <div class="column"><img class="demo" src="/img/cms/projekty/projekt.jpg" onclick="currentSlide(3)" alt="Mountains" /></div> <div class="column"><img class="demo" src="/img/cms/projekty/projekt.jpg" onclick="currentSlide(4)" alt="Lights" /></div> </div> </div>