fix(member-events): confirm actions reliably and normalize duplicate titles

public/assets/member-events-confirm.js

@@ -0,0 +1,28 @@
+(function () {
+    var decodeHtmlEntities = function (value) {
+        var textarea = document.createElement('textarea');
+        textarea.innerHTML = String(value || '');
+
+        return textarea.value;
+    };
+
+    var handleSubmit = function (event) {
+        var target = event.target;
+
+        if (!(target instanceof HTMLFormElement)) {
+            return;
+        }
+
+        var message = decodeHtmlEntities(target.getAttribute('data-confirm-message') || '');
+
+        if (!message) {
+            return;
+        }
+
+        if (!window.confirm(message)) {
+            event.preventDefault();
+        }
+    };
+
+    document.addEventListener('submit', handleSubmit, true);
+})();