Invalid argument in IE 7

------ c# code
 
 divThumbs.InnerHtml = String.Concat("<a href=\"#\" onclick=\"mainScreen.LoadServerControlHtml('Management',{'pageID':3,'data':" + xDocList[i].Attributes["id"].InnerText + "},'methodHandlers.BeginRecieve');\" onmouseover=\"setClassName('ctl00_mainContent_" + _docListCnt + "','managmentThumbGlow');\" onmouseout=\"setClassName('ctl00_mainContent_" + _docListCnt + "','managmentThumb');\"><img src=\"images/", xDocList[i].ChildNodes[2].InnerText, "\" border=\"0\" /><a/>");
 
 
-------- actual generated code
 
    <!-- start little thumbs //-->
 
        <div class="plcHolder"><div id="ctl00_mainContent_1" class="managmentThumb"><a href="#" onclick="mainScreen.LoadServerControlHtml('Management',{'pageID':3,'data':5},'methodHandlers.BeginRecieve');" onmouseover="setClassName('ctl00_mainContent_1','managmentThumbGlow');" onmouseout="setClassName('ctl00_mainContent_1','managmentThumb');"><img src="images/ourpeople/Grant-glover.jpg" border="0" /><a/></div><div class="namesText">Wayne Sidwell</div><div class="titleText">Executive Chairman & Chief Executive Officer</div></div><div class="plcHolder"><div id="ctl00_mainContent_2" class="managmentThumb"><a href="#" onclick="mainScreen.LoadServerControlHtml('Management',{'pageID':3,'data':6},'methodHandlers.BeginRecieve');" onmouseover="setClassName('ctl00_mainContent_2','managmentThumbGlow');" onmouseout="setClassName('ctl00_mainContent_2','managmentThumb');"><img src="images/ourpeople/Grant-glover.jpg" border="0" /><a/></div><div class="namesText">Steve Rees</div><div class="titleText">Chief Operating Officer</div></div><div class="plcHolder"><div id="ctl00_mainContent_3" class="managmentThumb"><a href="#" onclick="mainScreen.LoadServerControlHtml('Management',{'pageID':3,'data':7},'methodHandlers.BeginRecieve');" onmouseover="setClassName('ctl00_mainContent_3','managmentThumbGlow');" onmouseout="setClassName('ctl00_mainContent_3','managmentThumb');"><img src="images/ourpeople/Grant-glover.jpg" border="0" /><a/></div><div class="namesText">Kerry Smith</div><div class="titleText">Non Executive Director</div></div>
        <!-- end little thumbs //-->