<head>
<script language="javascript">
function check_ip(ipval){
    document.isp_form.action='http://whois.nic.or.kr/result.php';
    document.isp_form.method='post';
    document.isp_form.target='_blank';
    document.isp_form.domain_name.value = ipval;
    document.isp_form.submit();
    document.isp_form.action='';
    document.isp_form.method='';
    document.isp_form.target='';
}
</script>
</head>

<body>
<form name="isp_form"><input type=hidden name="domain_name" value=""></form>

<a href='javascript:void(0)' OnClick="check_ip('아이피주소')">아이피주소</a>
</body>

Post로 ip 값을 넘겨줘야함..

Get방식은 안먹음.