I had a quick question about my regression of panel data. I am using the fixed effects model to analyse data for 15 regions over the span of 7 years. I do not want to hold time constant but I do want to account for any regional differences between regions by holding cross-sections fixed. 

I am new to gretl and am not sure how to do this. When prompted by gretl, before running my regression I did not tick the "time dummy" box, however I cannot find an option for holding cross-sections fixed. When I enter dummies myself for regions they are omitted due to collinearity.

Thanks for your help

Ash