two fixed columns, horizontal scroll

Comes from http://jsbin.com/uxecel/4/edit?html,css,output

by brianlmerritt

HTML

<div class="outer">
  <div class="inner">
    <table>
        <tr>
          <th class="hard_left">Header A</th>
          <th class="next_left">Header B</th>
          <th>Header C</th>
          <th>Header D</th>
          <th>Header E</th>
          <th>Header A</th>
          <th>Header B</th>
          <th>Header C</th>
          <th>Header D</th>
          <th>Header E</th>
        </tr>
        <tr>
          <td class="hard_left">col 1 - A</td>
          <td class="next_left">col 2 - A</td>
          <td>col 3 - A</td>
          <td>col 4 - A</td>
          <td>col 5 - A</td>
          <td>col 1 - A</td>
          <td>col 2 - A</td>
          <td>col 3 - A</td>
          <td>col 4 - A</td>
          <td>col 5 - A</td>
        </tr>
        <tr>
          
          <td class="hard_left">col 1 - B</td>
          <td class="next_left">col 2 - B</td>
          <td>col 3 - B</td>
          <td>col 4 - B</td>
          <td>col 5 - B</td>
          <td>col 1 - A</td>
          <td>col 2 - A</td>
          <td>col 3 - A</td>
          <td>col 4 - A</td>
          <td>col 5 - A</td>
        </tr>
        <tr>
          
          <td class="hard_left">col 1 - C</td>
          <td class="next_left">col 2 - C</td>
          <td>col 3 - C</td>
          <td>col 4 - C</td>
          <td>col 5 - C</td>
          <td>col 1 - A</td>
          <td>col 2 - A</td>
          <td>col 3 - A</td>
          <td>col 4 - A</td>
          <td>col 5 - A</td>
        </tr>
        <tr>
          <td class="hard_left">col 1 - A</td>
          <td class="next_left">col 2 - A</td>
          <td>col 3 - A</td>
          <td>col 4 - A</td>
          <td>col 5 - A</td>
          <td>col 1 - B</td>
          <td>col 2 - B</td>
          <td>col 3 - B</td>
          <td>col 4 - B</td>
          <td>col 5 - B</td>
        </tr>
        <tr>
          <td class="hard_left">col 1 - A</td>
          <td class="next_left">col 2 - A</td>
          <td>col 3 - A</td>
          <td>col 4 - A</td>
 ...

CSS

table {
  table-layout: fixed; 
  width: 100%;
  *margin-left: -100px;/*ie7*/
}
td, th {
  vertical-align: top;
  border-top: 1px solid #ccc;
  padding:10px;
  width:100px;
}
th {
/*  position:absolute;
  *position: relative; /*ie7*/
/*  left:0; */
  width:100px;
}
.hard_left {
  position:absolute;
  *position: relative; /*ie7*/
  left:0; 
  width:100px;
}
.next_left {
  position:absolute;
  *position: relative; /*ie7*/
  left:100px; 
  width:100px;
}
.outer {position:relative}
.inner {
  overflow-x:scroll;
  overflow-y:visible;
  width:400px; 
  margin-left:200px;
}