限制页面中的复选框至少选择一个

<script language="javascript">

 function CheckSelect()
 {
  var tmpName="";
  for (var i=0;i<document.form1.length;i++)
  {
   if (document.form1.elements[i].checked == true)
   {
    tmpName += document.form1.elements[i].name + ",";
   }
  }

  if (tmpName == "")
  {
  alert("Please select one item at least!");
  return false;
  }

  return true;
 }

</script>