Need to add a new check for http://localhost to display a javascript message

I am doing a check on all hreh tags that do not in end in .com.  So if they do not end in .com I need to show a message.
I can add .com without any issues, but when I do http://localhost (for testing in development) it is not working. Basically if they are in development I DO NOT want the confirm message to fire:
$('a.externalLinkFunctionalityEnabled').click(function (e) { // Check if the link's href property doesn't contain ".com" if (($(this).attr('href').indexOf('.com') < 0) ) { // if (!confirm()) { // If the user cancels, prevent navigation e.preventDefault(); } } });