Confirm before deleting a post

src/http/tpl/posts-manage.html

@@ -1,4 +1,10 @@
 {{ define "body" }}
+  <script>
+    function confirmDelete(event) {
+      if (!confirm("Are you sure you want to delete this post?"))
+        event.preventDefault();
+    }
+  </script>
 
   <p>
     <a href="{{ BlogURL "admin" }}">Back to Admin</a>
@@ -34,7 +40,11 @@
             action="{{ PostURL .ID }}?method=delete"
             method="POST"
             >
-            <input type="submit" value="Delete" />
+            <input
+              type="submit"
+              value="Delete"
+              onclick="confirmDelete(event)"
+              />
           </form>
         </td>
       </tr>