added a js funct

static/js/vision.js

+function toggleLang() {
+   var elementsIT = document.getElementsByClassName("desc_it");
+   var elementsEN = document.getElementsByClassName("desc_en");
+   lan_sel = document.getElementById("lang_select");
+   stateIT = elementsIT[0].style.display;
+
+   for (var i = 0; i < elementsIT.length; i++) {
+     if (stateIT == "none") {
+       elementsIT[i].style.display = "block";
+       elementsEN[i].style.display = "none";
+     }
+     else {
+       elementsIT[i].style.display = "none";
+       elementsEN[i].style.display = "block ";
+     }
+   }
+
+   if (stateIT == "none")
+     lan_sel.style.backgroundImage = 'url(../img/flaguk.png)';
+   else
+     lan_sel.style.backgroundImage = 'url(../img/flagit.png)';
+}

static/js/vision.min.js

+function toggleLang(){var c=document.getElementsByClassName("desc_it");var a=document.getElementsByClassName("desc_en");lan_sel=document.getElementById("lang_select");stateIT=c[0].style.display;for(var b=0;b<c.length;b++){if(stateIT=="none"){c[b].style.display="block";a[b].style.display="none"}else{c[b].style.display="none";a[b].style.display="block "}}if(stateIT=="none"){lan_sel.style.backgroundImage="url(../img/flaguk.png)"}else{lan_sel.style.backgroundImage="url(../img/flagit.png)"}};
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