HTML - Ie Coming Up With Strange Error

.overlapTabs{ border-bottom: 1px solid  #bbb8a9; float: left; padding-top: 8px;}
 .overlapTabs ul{padding: 0; list-style-type: none; font-family: Tahoma, sans-serif, serif; font-size: 90%; margin: 0; font-weight: normal;}
 .overlapTabs li{display: inline;}
 .overlapTabs li a{padding: 3px 8px 3px 15px; text-decoration: none; padding-right: 40px; /*extra right padding to account for curved right edge of tab image*/ color:  #666666; background: transparent url(images/css/righttabdefault.gif) 100% 1px no-repeat; /*give illusion of shifting 1px down vertically*/ border-left: 1px solid  #dbdbd5; position: relative; display: block; float: left; margin-left: -19px; /*shift tabs 19px to the left so they overlap*/ left: 19px;}
 .overlapTabs li a:visited{}
 .overlapTabs li a:hover{text-decoration: underline;}
 .overlapTabs li .selected a{ /*selected tab style*/ color: black; z-index: 100; /*higher z-index so selected tab is topmost*/ top: 1px; /*Shift tab 1px down so the border beneath it is covered*/ background: transparent url(images/css/righttabselected.gif) 100% 0 no-repeat;}
 .overlapTabs li .selected a:hover{text-decoration: none;}

<span class="overlapTabs">
                <ul>
                <li class="selected"><a href="/?">Home</a></li>
                <li><a href="link2">link2</a></li>
                <li><a href="link3">link3</a></li>
                </ul>

              </span>

  <script language="JavaScript" type="text/javascript">
<!--

/***********************************************
* Required field(s) validation v1.10- By NavSurf
* Visit Nav Surf at http://navsurf.com
* Visit http://www.dynamicdrive.com/ for full source code
***********************************************/

function formCheck(formobj){
 // Enter name of mandatory fields
 var fieldRequired = Array("Name", "Surname", "Address", "Town", "Province", "Post Code", "Telephone", "Email", "Selection", "Details");
 // Enter field description to appear in the dialog box
 var fieldDescription = Array("Name", "Surname", "Address", "Town", "Province", "Post Code", "Telephone", "Email", "Selection", "Details");
 // dialog message
 var alertMsg = "Please complete the following fields:\n";
 
 var l_Msg = alertMsg.length;
 
 for (var i = 0; i < fieldRequired.length; i++){
  var obj = formobj.elements[fieldRequired[i]];
  if (obj){
   switch(obj.type){
   case "select-one":
    if (obj.selectedIndex == -1 || obj.options[obj.selectedIndex].text == ""){
     alertMsg += " - " + fieldDescription[i] + "\n";
    }
    break;
   case "select-multiple":
    if (obj.selectedIndex == -1){
     alertMsg += " - " + fieldDescription[i] + "\n";
    }
    break;
   case "text":
   case "textarea":
    if (obj.value == "" || obj.value == null){
     alertMsg += " - " + fieldDescription[i] + "\n";
    }
    break;
   default:
   }
   if (obj.type == undefined){
    var blnchecked = false;
    for (var j = 0; j < obj.length; j++){
     if (obj[j].checked){
      blnchecked = true;
     }
    }
    if (!blnchecked){
     alertMsg += " - " + fieldDescription[i] + "\n";
    }
   }
  }
 }

 if (alertMsg.length == l_Msg){
  return true;
 }else{
  alert(alertMsg);
  return false;
 }
}
// -->
</script>