When you create a task use the Task->Edit tab to specify a task handler. 

To assign an existing task :

• Click the Task -> Messages tab.
• Choose a new task handler.
• Click the Save button.

You can't assign a task if:

• You do not have permissions to add messages for the task (Statuses -> Edit tab in the User Management mode).
• You do not have permissions to change the task handler (Workflows -> Permissions tab in the Task Management mode, Statuses -> Edit tab in the User Management mode).
• There are no message types available for the task in the current state (Workflow -> Transitions tab in the Task Management mode).
• There are no available handlers for this task (Access Control tab in the Task Management mode).

• Task Concepts
• Adding Comments to a Task
• Setting Default Handler for a Project
• Restricting Handler List
• Receiving E-Mail Notification when Tasks Change
• Task Properties
• Message Properties