Guided Procedure

HI,

Iam facing the issues in Guided procedure.I have two Action.The Action two is Assigned to two users.Both the user get the Action in the UWL and both the user are possible to edit the Action.If one user completed the Action,the Action assign for the second user also completed.These things are working fine.I need to solve other issue.If one user edit the action i need to provide some information to other user ie.the Action is in Processing by other user.(or) If one user edit the Action at the same time the second user open the same action in his UWL the Action is in non editable mode.please provide the suggession for these issue.Its urgent.

Thanks and Regards,

Satheshkumar.R