JS判断RadioButtonList是否有选中项

<script type="text/javascript">
function checkra()
        {
             var rbltable = document.getElementByIdx("rbType");
             var rbs = rbltable.getElementsByTagName_r("Input");
             var result = false;
             for (var i = 0; i < rbs.length; i++) {
                 if (rbs[i].checked) {
                     result = true;
                     break;                 }
            }
           
            return result;
        }
   </script>

<script type="text/javascript">
   function checkvalue()
{
    var condITion='';
for (var i=0 ; i <form1.elements.length;i++)
{
if (form1.elements[i].type=="radio")
{
if (form1.elements[i].checked )
    {
    condITion=true;
    break;
    }
}
}
    if(!condITion)
    {
        alert("请选择咨询类型");
        return false;
    }
</script>