Dear Statalist

I'm currently trying to plot a two-way interaction graph.
My logit regression code is thus:
Code:
xtlogit div_ro c.nk i.wosjv c.nk##i.wosjv c.fsts c.nk##c.fsts c.log_age c.log_totalassets c.mkttobook c.orgslack c.financialleverage c.countries c.econgrowth c.cr3 c.exchangerate, re
Results are thus:

Array

I'm basically trying to plot a graph with the dependent variable in the y-axis, variable nk in the x-axis and two separate lines based on the degree of the variable fsts.

I have tried the code
Code:
margins, at(nk=(8(13)77) fsts=(0.3693356 0.8287758))
where nk ranges from 8 to 77 and the numbers behind fsts represents plus/minus one standard deviation from the mean value of fsts.
The results are thus:

Delta-method
Margin Std. Err. z P>z [95% Conf. Interval]

_at
1 .2223508 .0893532 2.49 0.013 .0472218 .3974799
2 .2223508 .0893532 2.49 0.013 .0472218 .3974799
3 .2223508 .0893532 2.49 0.013 .0472218 .3974799
4 .2223508 .0893532 2.49 0.013 .0472218 .3974799
5 .2223508 .0893532 2.49 0.013 .0472218 .3974799
6 .2223508 .0893532 2.49 0.013 .0472218 .3974799
7 .2223508 .0893532 2.49 0.013 .0472218 .3974799
8 .2223508 .0893532 2.49 0.013 .0472218 .3974799
9 .2223508 .0893532 2.49 0.013 .0472218 .3974799
10 .2223508 .0893532 2.49 0.013 .0472218 .3974799
11 .2223508 .0893532 2.49 0.013 .0472218 .3974799
12 .2223508 .0893532 2.49 0.013 .0472218 .3974799


Fundamentally, the results are giving me identical margins, which result in a graph shaped liked this:

Array

I have tried using the Postestimation function in Stata as well, but am getting similar results.
I must ask for your help.
I do apologize for the sloppiness in the presentation. It is my first time posting and I am not quite sure how to post Stata results.
Thank you in advance.