The discount amount should be stored in a session variable rather than using the recordset value.
use the Set Session value server behavior to capture the value from the recordset, then use the session variable in the discount.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.