function addtb()
{
  document.selection.empty();
  document.getElementById("TextEditor").focus();
  cmd = 'InsertInputText';
  document.getElementById('TextEditor').document.execCommand(cmd,'true');
 
  var TE = document.getElementById('TextEditor');
  var TEcn=TE.children;
 
  for (i=0;i<TEcn.length;i++)
  {
    n++;
    if(TEcn[i].id == "")
    TEcn[i].id = "tb" + n;
  }
 
}