Working on a program which helps with the running of a supermarket, which includes sale of alcohol

With regard to alcohol, it is not permissible to drink it,
carry it, sell it, buy it or help with it in any way whatsoever, such as
documenting it or recording it in a book or on a computer, because of the
warning and curse which is mentioned concerning it, as it was narrated by
Abu Dawood (3674) and Ibn Maajah (3380) that Ibn ‘Umar (may Allaah be
pleased with him) said: The Messenger of Allaah (blessings and peace of
Allaah be upon him) said: “May Allaah curse wine, the one who drinks it, the
one who pours it, the one who sells it, the one who buys it, the one who
squeezes (the grapes etc), the one for whom it is squeezed, the one who
carries it and the one to whom it is carried.” Classed as saheeh by
al-Albaani in Saheeh Abi Dawood.  

If part of your job is to record or process things that have
to do with alcohol, it is not permissible for you to do that. 

But if you can work and avoid anything that has to do with
alcohol so that others can deal with that, there is nothing wrong with it.
It is not permissible for them to force you to pay three months salary,
because your leaving the job is only because of them; they are the ones who
have transgressed the sacred limits of Allaah and disobeyed Him. 

If you cannot find any way to disassociate from them and you
do not have any money with which to pay this amount, and that would result
in great harm such as imprisonment, then you are being forced to do that,
and there is no sin on you if you work with them for three months. But if
your not paying this money will not result in any major harm, then do not
work with them, because in that case you are not being forced. 

We ask Allaah to bless you with halaal provision and
beneficial work, and to increase you in knowledge and guidance.  

And Allaah knows best.