Assigning a new number to an attribute as a geoprocessing function

Discussion created by Lori.Koepsell on Jan 13, 2014
I have a model that I will use to publish as a geoprocessing service.  I first select two objects from a database and create a new datalayer from that selection.  I now want to allow a user, online, to pick one of four values to add to a particular attribute of that new datalayer in order for the second tool to run.  Right now I have added "Calculate Field" with the mathematical equation hard coded for one of the four values.  And the model runs perfectly with that, however I can't seem to find the way to allow a user to change it.  I thought "Create Variable" = "Long" as an input might do it but I don't know how to connect that Variable to the Calculate Field tool.