how to calculate a scripted custom field and system custom field?

[mozhde.a]

In fact I have got two custom field which one of them is scripted custom field, and I want to calculate them.Also I need to have some conditions with the scripted one but unfortunately i could do nothing!!!

for example when I want to set a condition on transition in workflow again my condition does not work!!

whats the problem with it? 

[Vasiliy Zverev]

1. Could you provide the condition?
   1. is it a custom script condition
   2. or simple script condition
      1. Try use assert