Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
To start with, I need to know the version of mac osx you have on your machine, you can check as follows.Click the apple sign at the top left of your screen, then click about this mac. And then where it says version, send that to me as a reply.
Also, have you tried following these steps to reconnect the machine to your new wireless network using the connection tool?
If step 2 doesnt fix the issue.. Let me know what it says in the wlan report for Gateway, ip address and dns server..
Hello again, I never heard back from you after you read my response? Did you still need help with this issue, if so please respond. Otherwise please remember to click and submit a 5 star rating to show I was able to assist you, and to close out the question.