Advice on Calculation for Watch Request

Hi,

I have created a Watch Request Process similar to Incident, only problem is for Request we have a pre-condition to prevent Requests being fulfilled with open tasks attached.

The way forward would be to insert a calculation to ignore a particular Task lifecycle.

I came up with the following code but though the syntax is valid, it produces an error whilst testing the Calculation.

import System
static def GetAttributeValue(Request):
 Value = ''
 if Request.Tasks.Lifecycle.Title == 'Request Watch List Task':  Value = 'Yes'
 if Request.Tasks.Lifecycle.Title == 'Request Task':  Value = 'No'
 return Value

Error Message:

Error on line 4: Field

'Touchpaper.Framework.Data.DataObjectListProxy.Lifecycle' not found'

When testing the calculation it present a list of Requests, maybe its can't process as the Request could have multiple tasks??

Any advice would be much appreciated

Thanks