anchor.diff:  </div>
   <!-- la zone chat -->
   <div id="session-chat" data-role="page">
  -    <div data-role="header">
  +    <div data-role="header" data-id="head" data-position="fixed">
           <div data-role="navbar">
               <ul>
                   <li><a href="#session-zone" data-transition="slideup">Zone de dessin</a></li>
  
positive.code:         </div>
      </div>
      <div data-role="content">
          <div id="session-brush" >
              <a href="#" data-role="button" data-inline="true" data-theme="c" data-icon="grid" data-iconpos="notext" id="brush">Afficher la palette</a>
          </div>
          <canvas id="session-drawing"></canvas>
      </div>
  </div>
  <!-- la vue globale -->
  <div id="session-global" data-role="page">
      <div data-role="header">
          <div data-role="navbar">
              <ul>
                  <li><a href="#session-zone" data-transition="slideup">Zone de dessin</a></li>
  
negative.code: 
  <!-- la zone de dessin -->
  <div id="session-zone" data-role="page">
      <div data-role="header" data-id="head" data-position="fixed">
          <div data-role="navbar">
              <ul>
                  <li><a href="#session-zone" data-transition="slideup" class="ui-btn-active ui-state-persist">Zone de dessin</a></li>
  