New to a Mac - Connecting to AirPort

I have recently purchased a MacBook Pro after being a lifelong Dell laptop user. My roommate has always had a wireless router that both of us used to connect our laptops too. It is secure and requires a password to use.

Now, when I try to connect using my MacBook, the AirPort asks for the password, which I enter, and it says it is connected and gives me an IP address (the bars are full too).....however, I can not get onto any internet site using Safari or connect to iTunes.

When I disconnect and connect to an un-secure network in my building (an Apple Network according to the name), I am able to get to sites and iTunes instantly.

Obviously I want to connect to our own wireless connection. Am I doing something wrong or missing something? Any help or assistance is appreciated.

What kind of security does your roommate have setup on the router? WEP? WPA? WPA2?

Some things to check:

Open System Preferences, Network. Click on Airport (left side). Is the network name showing up in the Network Name box? And, what is showing up in the box above that says "Location"?

Next, click on the Advanced tab below. Click the Airport tab. The network name and type of security should show there. Click on the TCP/IP tab.

In the Configure IPv4 box you should have "Using DHCP"

Post back.

Regards.