pool object in a system

[Ozlem]

I want to run a nonlinear ls regression for a pooled cross section time series data. I created a pool object. I think the only way to run nonlinear regression for this data is a system object. When I use varname_? in the system object, it says it is not defined. How do I define it? Pool is already in my workfile.

[EViews Gareth]

You can not perform system estimation, or non-linear estimation with Pools. Use a panel workfile instead.

[Ozlem]

OK. Thanks!