diff --git a/Pages.hs b/Pages.hs
--- a/Pages.hs
+++ b/Pages.hs
@@ -19,6 +19,8 @@
       [ header <<
          [ thetitle << title_text
          , thelink ! [rel "stylesheet", thetype "text/css", href (relativeURLOf "style.css")] << ""
+         , script ! [src "http://code.jquery.com/jquery-1.4.2.min.js", thetype "text/javascript"] << ""
+         , script ! [src (relativeURLOf "ui-tweaks.js"), thetype "text/javascript"] << ""
          ]
       , body <<
          [ thediv ! [identifier "header"] <<
@@ -36,8 +38,8 @@
    in page_template title_text <<
          [ p ! [identifier "help"] << "Help" `at` "?help"
          , thediv <<
-            [ p << ("This tool allows to generate free theorems for sublanguages of Haskell as described " +++ "here" `at` "?help"  +++ ".")
-            , p << ("The source code of the underlying library and a shell-based application using it is available " +++ "here" `at` hackage "free-theorems" +++ " and " +++ "here" `at` hackage "ftshell" +++ ".")
+            [ p << ("This tool allows to generate free theorems for sublanguages of Haskell. See the " +++ "help page" `at` "?help"  +++ " for details.")
+            , p << ("The source is available at hackage as " +++ ("free-theorems-webui" `at` hackage "free-theorems-webui") +++ ". See also: " +++ ("free-theorems (library)" `at` hackage "free-theorems") +++ " and " +++ ("ftshell (shell interface)" `at` hackage "ftshell") +++ ".")
             , p << ("You may also want to try the following related tools:" +++ ulist << [ li << "Automatically Generating Counterexamples to Naive Free Theorems" `at` "http://www-ps.iai.uni-bonn.de/cgi-bin/exfind.cgi"
                                                                                          , li << "Taming Selective Strictness" `at` "http://www-ps.iai.uni-bonn.de/cgi-bin/polyseq.cgi"
                                                                                          ])
diff --git a/TypesetAsImage.hs b/TypesetAsImage.hs
--- a/TypesetAsImage.hs
+++ b/TypesetAsImage.hs
@@ -5,9 +5,8 @@
 import System.IO (openTempFile, hClose, hPutStr, getContents)
 import System (system)
 import Data.List (intercalate)
-import Data.Char
--- Needs package: base64-string
-import Codec.Binary.Base64.String as Base64
+import qualified Data.ByteString as BS
+import qualified Codec.Binary.Base64 as Base64
 import Text.XHtml
 
 import System.IO.Unsafe (unsafeInterleaveIO)
@@ -25,17 +24,22 @@
  where
    asHtml pngImage =
      let
-       header = drop 16 pngImage
-       w = sum $ zipWith (*) [256^3, 256^2, 256, 1] $ map ord $ take 4 header
-       h = sum $ zipWith (*) [256^3, 256^2, 256, 1] $ map ord $ take 4 $ drop 4 header
+       -- Extract width and height from the PNG header
+       header = BS.drop 16 pngImage
+       w = valueOf $ BS.take 4 header
+       h = valueOf $ BS.take 4 $ BS.drop 4 header
+       valueOf = sum . zipWith (*) [256^3, 256^2, 256, 1]
+                     . map fromEnum
+                     . BS.unpack
      in
-       image ! [ src $ "data:image/png;base64," ++ Base64.encode pngImage
+       image ! [ src $ "data:image/png;base64," ++ Base64.encode (BS.unpack pngImage)
                , alt formula
                , width  (show (w `div` 2))
                , height (show (h `div` 2))
                ]
 
 
+typesetAsPNG :: String -> IO BS.ByteString
 typesetAsPNG formula = unsafeInterleaveIO $ do
    tmp_dir <- getTemporaryDirectory
    (tempPath, tempHandle) <- openTempFile tmp_dir "temp.tex"
@@ -54,7 +58,7 @@
    system $ "dvipng -x 2400 -T tight -z 9 -bg transparent -o " ++ pathTo "png" ++ " " ++ pathTo "dvi" ++ " > /dev/null"
    removeFile $ pathTo "dvi"
 
-   pngImage <- readFile $ pathTo "png"
+   pngImage <- BS.readFile $ pathTo "png"
    removeFile $ pathTo "png"
 
    return pngImage
diff --git a/free-theorems-webui.cabal b/free-theorems-webui.cabal
--- a/free-theorems-webui.cabal
+++ b/free-theorems-webui.cabal
@@ -1,5 +1,5 @@
 Name:     free-theorems-webui
-Version:  0.1
+Version:  0.2
 
 Synopsis: CGI-based web interface for the free-theorems package.
 Description:
@@ -16,6 +16,7 @@
    To start it locally for offline usage, just call "free-theorems-webui" after installation. (This needs python)
 License:    PublicDomain
 Category:   Language
+Author:     Matthias Bartsch
 Maintainer: bartsch@cs.uni-bonn.de
 
 Cabal-Version: >= 1.2
@@ -24,6 +25,7 @@
 
 Data-files:
    style.css
+   ui-tweaks.js
    lambdaTeX.tex
    runLocalServer.py
 
@@ -63,7 +65,7 @@
                 , directory     >= 1.0.0.2
                 , filepath      >= 1.1.0.1
                 , xhtml         >= 3000-2-0-1
-                , base64-string >= 0.2
+                , dataenc
                 , haskell98
    if flag(our_server)
       hs-source-dirs: . our_server_config
diff --git a/style.css b/style.css
--- a/style.css
+++ b/style.css
@@ -1,25 +1,23 @@
-body { padding:0px; margin: 0px; }
+body { padding: 0px; margin: 0px; }
 
-/* renamed from "div.top" */
 #header {
-   margin:0px; padding:10px; margin-bottom:20px;
-   background-color:#efefef;
-   border-bottom:1px solid black;
+   margin: 0px; padding: 10px; margin-bottom: 20px;
+   background-color: #efefef;
+   border-bottom: 1px solid black;
 }
 
-/* renamed from "span.title" */
 h1 {
    display: inline;
    font-size: xx-large;
    font-weight: bold;
 }
-/* renamed from "span.subtitle" */
 h2 {
    display: inline;
    font-size: large;
    font-weight: normal;
    padding-left:30px;
 }
+
 #help {
    position: absolute;
    top:   0em;
@@ -27,29 +25,23 @@
 }
 
 #content > div {
-   border:1px dotted black;
-   padding:10px; margin:10px;
+   border: 1px dotted black;
+   padding: 10px; margin: 10px;
 }
 
-/* renamed from "div.submain" */
-#footer { padding:10px; margin:11px; }
-
-p.subtitle { font-size:large; font-weight:bold; }
-
-input.type { font-family:monospace; }
-
-input[type="submit"] { font-family:monospace; background-color:#efefef; }
+input.type, textarea { font-family: monospace; }
 
-span.mono { font-family:monospace; }
+input[type="radio"], input[type="checkbox"] {
+   margin-left: 5px;
+}
 
 pre {
-   margin:10px; margin-left:20px; padding:10px;
-	border:1px solid black;
+   margin: 10px; margin-left: 20px; padding:10px;
+	border: 1px solid black;
 }
 
 p { text-align:justify; }
 
-/* Added later */
 .error { background: #fcc; }
 
 textarea { height: 20em; width: 30em; }
diff --git a/ui-tweaks.js b/ui-tweaks.js
new file mode 100644
--- /dev/null
+++ b/ui-tweaks.js
@@ -0,0 +1,28 @@
+$(document).ready(function(){
+
+   var disableStyleOptions = function(shouldBeDisabled) {
+      /* Disable (or enable) the options for selecting a theorem style */
+      $("input[name=style]").attr("disabled", shouldBeDisabled);
+   };
+
+   /* When the selected language model changes,
+    * disable the options for selecting a theorem style for "basic"
+    * but enable them for "fix" and "seq".
+    */
+   $("input[value=basic]").change(function(){
+      disableStyleOptions(true);
+   });
+   $("input[value=fix]").change(function(){
+      disableStyleOptions(false);
+   });
+   $("input[value=seq]").change(function(){
+      disableStyleOptions(false);
+   });
+
+   /* Trigger the change event on the pre-selected option
+    * to have the style options enabled/disabled correctly
+    * after the page is loaded.
+    */
+   $("input[name=model]:checked").change();
+
+});