Tigger sub-tasks through other sub-task status

[Jimit Mehta]

I am trying to create a workflow wherein:

Once I create an issue, 

First it should automatically create a sub-task (already figured out)

Then once the above sub-tasks status changes to "Closed/Done", then it should automatically create another sub-task under the same issue and so on.

All this needs to be done only under the same request type.

Help!

thanks,