Use of script output value as variable in field calculator

Discussion created by rcmiedema on Dec 13, 2011
I´m generating a model for use in a geoprocessing service (ArcGIS 9.3). In this model I will use several times the Field Calculator to get values in a new defined field (type double). The value I want to be calculated is the output of a Python script a included in the model.
The script converts string values (input parameters in the model) into doubles. So the resulting double I would like to use in the Field Calculator in the Expression as variable, i.e. %OUTPUT_VALUE%.
The model fails when trying to calculate the field:
ERROR 999999: Error executing function.
A locator with this name does not exist.
Failed to execute (Calculate Field (2)).

How do I make this work?