Firstly are you absolutely sure that you are typing the password correctly? Type it into a word document and then copy and paste it to be absolutely sure. When you say password, are you using the passphrase to enable it to access the router wirelessly, or doyou mean the hexidecimal no that is usually on the bottom of the router?
When you say it will not go online - are you trying by ethernet or do you mean wirelessly? If wirelessly, is this enabled on your laptop?
I suggest that you try to connect by ethernet first and then try wirelessly.
Have you tried to reset the router?