JS can not cross-domain access to the IP address using jquery _javascript tips

Get IP address, JS can also get the client IP address, we know that JS can not cross the domain, so here with the help of jquery, really can achieve access to IP address, code as follows, has passed the test:

<script language= "javascript" src= "Http://www.jb51.net/jslib/jquery/jquery.js" ></script> 
< Script language= "JavaScript" > 
jQuery (Function ($) { 
var url = ' http://chaxun.1616.net/s.php?type=ip& Output=json&callback=?&_= ' +math.random (); 
$.getjson (URL, function (data) { 
alert (data). Ip); 
}; 
</script>