可以校验你在你的文本框上输入的数据是否是正确Ip
function check_ip()
{
var i;
var ip=document.getElementById('Ip').value;
var node = document.getElementById("ip_span");
i = ip.length;
if(i==0)
{
alert("警告：请输入IP地址");
}
alert(ip);
var re=/^(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])$/ ;
if(re.test(ip))
{
node.firstChild.nodeValue = "Ip地址输入正确";
}
else
{
node.firstChild.nodeValue = "非法Ip地址";
}
}