Hi, I use default TaskController for submitting parameters collected on task form. I do not know how I was missing this issue all this time, but it just happened :) so this line in mentioned class caused me headache + couple of hours: | if (value!=null) { | log.debug("submitting task variable '"+mappedName+"' to process variable '"+variableName+"', value '"+value+"'"); | contextInstance.setVariable(variableName, value, token); | } | which means, I guess, that if the variable in task variable map has value NULL, it will not be copied to token, or process instance variable. Now, if I have task form (jsp) with check boxes and I collect submitted fields by request.getParameter(), I want to NULL this value on process level, but simply it cannot do. I am sure there was a reason for implementing this behavior. If somebody knows, I would be happy to hear it. Now, I am going to sharp my pen and write my own implementation of Task Controller. And yes, user doc says: anonymous wrote : | When the user ends the task, the task controller is responsible for updating the process variables based on the task instance data. | Thanks for comment, cheers and long live JBPM! milan View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4201972#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...