try fixing banners

contrib/static/nntpchan.js

@@ -21,6 +21,6 @@ function nntpchan_inject_banners(elem, prefix) {
   var banner = prefix + "static/banner_"+n+".jpg";
   var e = document.createElement("img");
   e.src = banner;
-  e.setAttribute("class", "nntpchan_banner");
+  e.id = "nntpchan_banner";
   elem.appendChild(e);
 }

contrib/static/site.css

@@ -321,3 +321,8 @@ textarea#reply-text {
 hr {
 	padding-bottom: 20px;
 }
+
+
+#nntpchan_banner {
+    align: center;
+}