<table id="table_container">
  <tr>
      <td colspan="2" style="height: 30px; valign: top;">
           <div id="menu_div"></div>
      </td>
  </tr>
  <tr>
      <td colspan="2" style="height: 10px;">
           <div id="space_div"></div>
      </td>
  </tr>
  <tr>
      <td style="width:250px; height: 100%; padding-top: 70px;">
         <div id="tree_div" style="valign: top; height: 100%;"></div>
      </td>
      <td rowspan="2" style="padding: 10px;">
          <div id="main_content_div" style="valign: top;">
          </div>
      </td>
  </tr>

var tree = Ext.create('Ext.tree.Panel', {
        id: 'tree_id',
        store: tree_store,
        width: 250,
        height: 500,
        autoScroll: true,
        renderTo: document.getElementById('tree_div'),
        useArrows: true,
        border: false,
        frame: false,
        rootVisible: true