code from SqSp site for search bar in header.

<div id="search-wrapper" data-kbjs-widget="search-widget" data-autocomplete="true" data-search-id="nav-search">
              <form action="/search-results">
                <button type="button" id="search-button"></button>
                <input type="text" id="nav-search-box" name="q" placeholder="Search">
                <p class="search-instructions hidden">Press enter</p>
              </form>