How to pass a dashboard parameter to a calculated field's expression in code

The following example demonstrates how to create a new dashboard parameter and pass it to a calculated field's expression.

In this example, the dashboard connects to the Northwind database and selects data from the 'SalesPerson' table. A new calculated field evaluated at a summary level returns 'TRUE' or 'FALSE' depending on whether on not the average discount exceeds the selected parameter value.