Fix #108 404.html button does not trigger the search

templates/404.html

@@ -22,7 +22,7 @@ Page does not exist at {{ SITENAME|striptags }} blog.
         <div class="input-append">
             <form action="{{ SITEURL }}/search.html" onsubmit="return validateForm(this.elements['q'].value)">
                 <input type="text" class="span12" placeholder="Search" name="q" id="tipue_search_input_404">
-                <button class="btn" type="button">Search</button>
+                <button class="btn" type="submit">Search</button>
             </form>
         </div>
     </div>