Script Logic: Time Dimension Issue

Hi,

How do I use the TIME dimension in the WHEN clause of Script logic? I have been trying to use the following script to check the prior period is the last period of the last fiscal year but it does not work.

*SELECT(%YR%,"[YEAR]",TIME,"[ID] = '%TIME_SET%'")

*XDIM_MEMBERSET TIME = TMVL(-1,%TIME_SET%)

*WHEN TIME.ID

*IS TMVL(-12,%YR%.12)

.....

ENDWHEN

My example is where the user enters 2015.01 as %TIME_SET%. My time dimension is maintained correctly. Please find a screenshot attached. So how do I use the Time dimension in the WHEN clause?

Please help!!!

Nicky