[Gretl-users] Probit forecasting

Gretl Community,   I am new to gretl and spent a great deal of time searching on this issue, but I figured maybe some of you could help. I am attempting to replicate a forecasting model using a probit regression. Please see link for a detailed description:   http://www.econbrowser.com/archives/2006/04/the_yield_curve.html   I created a binary file for recession, 1 indicating a recession, with NBER data. I am trying to predict a univariate analysis using the difference of 3 month tbill and 10 year tbill yields. I am using monthly data, whereas, most have used quarterly. I am trying to forecast 12 months ahead and also generate a "prob-of-recession vs spread" table which you can see in the link above.   I have devoted many hours searching and experimenting but I cannot figure out how they obtain this data. Any and all help is truly appreciated. Many Thanks   Don