I have a table that I'm loading via an AJAX call upon selecting an item in a SELECT.

The code works flawlessly in FF but in IE6, I get an error:
"Unknown runtime error"

What do I need to do to make this work in both browsers?

Code JavaScript:
function getRoster(){
  if(oXMLHTTP=getXMLHTTP()) {
    // the select that user chooses team
    var theselect          = document.getElementById("tid");
    // hidden form field to hold selected teamid
    var tiid               = document.getElementById("teamid");
    tiid.value             = theselect.value;
 
    // Go get the data
    oXMLHTTP.open('get', 'getroster.php?teamid='        + theselect.value);
    oXMLHTTP.onreadystatechange = AddRosterRows; 
    oXMLHTTP.send(null);
  }
}
 
function AddRosterRows(){
  if(oXMLHTTP.readyState == 4){ 
    var response      = oXMLHTTP.responseText;
    var tabBody       = document.getElementById("playertablebody");         
    var response      = oXMLHTTP.responseText;
 
    // Unknown runtime error occurs on next line if IE6.
    tabBody.innerHTML = response; 
 
    // Disable the dropdown only if there was a response
    if (response.length > 0) {
      var theselect          = document.getElementById("tid");
      theselect.disabled     = true;
    }
  }
}
The Table:
Code HTML4Strict:
<table width="400" border="0" cellpadding="1" cellspacing="0" class="playertable">
  <th class="stheader1" width="300" align="center">Player Name</th>
  <th class="stheader1" width="50" align="center">Jersey</th>
  <th class="stheader1" width="50" align="center">Age</th>
  <tbody id="playertablebody">
  </tbody>
</table>
Sample Data returned from getroster.php:
Code HTML4Strict:
<tr>
  <td class='player2'>
    <input type="hidden" name="pid[]" value="38"/>
    <input type="hidden" name="name[]" value="Jimmy pitcher"/>Jimmy pitcher
  </td>
  <td class='jersey2'><input type="text" size="3" name="jersey[]"/></td>
  <td class='age2'><input type="hidden" name="age[]" value="12"/>12</td>
</tr>
<tr>
  <td class='player1'>
    <input type="hidden" name="pid[]" value="37"/>
    <input type="hidden" name="name[]" value="Super Chicken"/>Super Chicken
  </td>
  <td class='jersey1'><input type="hidden" name="jersey[]" value="00"/>00</td>
  <td class='age1'><input type="hidden" name="age[]" value="9"/>9</td>
</tr>