Problem with using an output variable in HFSS script

Hello, I have a question about HFSS script. I have a problem when I want to use an output variable in a mathematical expression. I try to use the command "o.design.GetOutput VariableValue" to put the value of the "output variable" in a declared variable but it does not function.

Thanks a lot for an answer

Yes, it'is net convience,I find a programm problem monthes ago, and the Tech Support havn's solved it until now.
but you can find solution by yourself carefully