The port property represents the port number in the URL. This is not always present in all URLs.
<html> <head> <title> Using the port property of the Link object</title> </head> <body> <script language="JavaScript"> <!-- function showport(){ alert(document.links[0].port); } --> </script> Click the button to see the port number for the URL <form name="form1"> <a href=http://www.navioo.com> http://www.navioo.com</a> <br><br> <input type="button" name="port" value="Get Port Number" onClick='showport()'> <br> </form> </body> </html>