Query on Multithread operation in Workshop

[Vidya Vaidyanathan]

Hello,
        I find that in Sun-Workshop I am unable to use the next and the
step operations in case of multithread programs. The idea of using this is
to continously reset a variable to a predetermined value, immaterial of
the transactions on that variable. These are not getting enabled as step
option is unavailable.
        Please give me some insight into this problem.
        Thanks in advance
Regards,
Vidya