Rehab's for quitters?

Lindsay Lohan is behaving like a model patient at a strict Mormon rehab clinic - she's even reportedly cleaning the clinic's lavatories. Meanwhile, troubled singer, Amy Winehouse told a newspaper that her recent overdose was a wake-up call and she pledged to go clean. Do you think either of these stars have what it takes to stay off drink and drugs or will they be back to their partying ways? Have your say.