a bit of SQL help?

Hello smart people!

Our Tessitura guru moved on to other SQL pastures, and I need to make an edit to a SQL statement but don't know how.

So, I have this snippet of info:

       (SELECT a1.customer_no

        FROM   vs_package_history AS a1 WITH (NOLOCK)

        WHERE  a1.pkg_amt >= 400

I *think* need to change the pkg_amt to order amount, but don't know how to say that. Can you help??

Thanks in advance!