Notification after a Custom Form is completed

Is there a way to automatically send an email notification to a specific user once a task level custom form has been filled out? We have a form that we are asking people to fill out and then send an update letting us know it's completed but they keep forgetting to send the update after they fill out the form. We don't want to treat this like a request queue - we want it to be part of the task in the project plan. Veronica P