"Definition Expression" Flex 4.0 ArcGIS Viewer for Flex 2.1

[PaulLang]

Would like to do something like the enclosed link, but allow user to enter value of expression.
Where in the viewer should I insert my code?


http://geochalkboard.wordpress.com/2010/04/26/using-definition-expressions-in-the-agis-api-for-flex-...