Need a query to run reports the past two hours

Hi,

I need help in writing a simple SQL query to run reports for the past two hours. I realize if I use the following, I can get the past two hours.

SELECT DATEADD(HOUR, -2, GETDATE())AS [TwoHoursAgo]

How do you use the result of this in my next statements? These are the rest of the statements?

select column a, column b, column c
from nt_table
where timestamp > (This is where I want to use the result of the first querty. So if I can use the result of what ever resulting number I get above from the first query , my report will run the for the past two hours. How do I define this folowing "where timestamp >" .

Any help is greatly appreciated.

Thanks,

SQL newbie