diff --git a/copyparty/web/browser.js b/copyparty/web/browser.js
index 5d4d74b6..7a2f4360 100644
--- a/copyparty/web/browser.js
+++ b/copyparty/web/browser.js
@@ -317,7 +317,7 @@ function seek_au_sec(seek) {
 	if (mp.au === mp.au_native)
 		// hack: ogv.js breaks on .play() during playback
 		mp.au.play();
-};
+}
 
 
 function song_skip(n) {
@@ -329,7 +329,7 @@ function song_skip(n) {
 		play(mp.order.indexOf(tid) + n);
 	else
 		play(mp.order[0]);
-};
+}
 
 
 // hook up the widget buttons
@@ -618,13 +618,16 @@ function tree_neigh(n) {
 			break;
 		}
 	}
-	a += n;
-	if (a < 0)
-		a = links.length - 1;
-	if (a >= links.length)
-		a = 0;
+	if (act == -1)
+		return;
 
-	links[a].click();
+	act += n;
+	if (act < 0)
+		act = links.length - 1;
+	if (act >= links.length)
+		act = 0;
+
+	links[act].click();
 }
 
 
@@ -939,8 +942,7 @@ var treectl = (function () {
 			tree.style.top = Math.max(0, parseInt(atop)) + 'px';
 		}
 		else {
-			var wraph = parseInt(getComputedStyle(ebi('wrap').offsetParent).height),
-				top = Math.max(0, parseInt(wrap.offsetTop)),
+			var top = Math.max(0, parseInt(wrap.offsetTop)),
 				treeh = (winh - atop) - 4;
 
 			tree.style.top = top + 'px';
diff --git a/copyparty/web/up2k.js b/copyparty/web/up2k.js
index 600822bf..f2c3ebf4 100644
--- a/copyparty/web/up2k.js
+++ b/copyparty/web/up2k.js
@@ -374,7 +374,7 @@ function up2k_init(have_crypto) {
             for (var a = 0, aa = Math.min(20, bad_files.length); a < aa; a++)
                 msg += '-- ' + bad_files[a] + '\n';
 
-            if (files.length - bad_files.length <= 1 && /(android)/i.test(navigator.userAgent))
+            if (good_files.length - bad_files.length <= 1 && /(android)/i.test(navigator.userAgent))
                 msg += '\nFirefox-Android has a bug which prevents selecting multiple files. Try selecting one file at a time. For more info, see firefox bug 1456557';
 
             alert(msg);
diff --git a/copyparty/web/util.js b/copyparty/web/util.js
index 01538622..1aef3fa4 100644
--- a/copyparty/web/util.js
+++ b/copyparty/web/util.js
@@ -119,7 +119,7 @@ function crc32(str) {
         crc = (crc >>> 8) ^ crctab[(crc ^ str.charCodeAt(i)) & 0xFF];
     }
     return ((crc ^ (-1)) >>> 0).toString(16);
-};
+}
 
 
 function clmod(obj, cls, add) {