[FCK] undefined error

               <div>
                 <br />
                 <input id="txtTitleLightBox" style="width: 100%" type="text" />
               </div>

     var rel = oLink.rel;
     if (rel)
     {
       var type;
       if (rel.indexOf("[") > 0)
         type = rel.substring(0,rel.indexOf("["));
       else
         type = rel;
       var oE = GetE('rad'+type);
       if (oE)
       {
         GetE('txtTitleLightBox').value= title;
         GetE('txtGroupLightBox').value= rel.substring(rel.indexOf("[")+1, rel.indexOf("]"));
         GetE('chkLightBox').checked = true;
         GetE('rad'+type).checked = true;
       }
     }

   if (GetE('chkLightBox').checked && oLink)
   {
     var rel = "lightbox"
     var rad = document.getElementsByName('radLightBoxType')
     for (var i=0; i < rad.length; i++)
     {
       if (rad[i].checked)
       {
         rel = rad[i].value;
         break;
       }
     }

     oLink.title = title
     var title = GetE('txtTitleLightBox').value = title;
     oLink.rel = rel
     var group = GetE('txtGroupLightBox').value
     if (group)
     {
       oLink.rel += "[" + group + "]"
     }
   }

     oLink.title = title
     var title = GetE('txtTitleLightBox').value = title;

         GetE('txtTitleLightBox').value= title;

<a title="undefined" rel="lightbox" href="image/path"><img width="200" height="113" alt="" src="image/path" /></a>