Ok, i'm trying to do 1). myself this way:
I have a field SUPPLIER that takes value from another field in another table
i made dropdown list called filterSUPPLIER and made a button nearby with following script:
Perform Quick Find [table::filterSUPPLIER]
...that's all.... and it works, but with some bugs. It showing one supplier for me perfectly, but when I choose another one it shows me another supplier + the one I choose first time in the bottom.
Seems to be I need to reset my search in my script, but I'm not sure how can I?
My 2). is done easily by making SUMMARY field in footer. It shows exactly what I want it to show me in case if data filter correctly, but it is not and I can't get why ;(
Wouldn't it be better to perform a regular find for the supplier rather than a quickfind?
I'm not really familiar with it. How should my criteria look like?
FIND RECORDS WHEN - SUPPLIER = ....what? I tried to put Purchase orders::filterSUPPLIER there, but nothing happened. I think I'm wrong with operator here.
Try something like this
Enter Find Mode [ ]
Set Field [ SupplierTable::Supplier Name; Purchase orders::filterSUPPLIER ]
Perform Find 
Of course you will have to change SupplierTable::Supplier Name to whatever table and field contains your supplier names.
Thank you for advice!
I found another way. How do you think is it:
I made a script for a button SEARCH:
Set Variable [$supplier; Value:table::filterSUPPLIER]
Perform Find [Restore]
And perform find look like:
Action: Find records
Criteria: table::poSUPPLIER: [$supploer]
It works fine, but I'm not sure is it good way to perform like that?
That is essentially the same as what I suggested. Just a different way of scripting it. I don't think one way is any better than the other. Either way, you should be all set.
Good to know! Thank you for you help and time!