##########SEARCH######################
    if typeBookSearch.get() != "":
        dict['rodzaj'] = typeBookSearch.get()
    if publisherBookSearch.get() != "":
        dict['wydawca'] = publisherBookSearch.get()
    if yearBookSearch.get() != "":
        dict['rok publikacji'] = yearBookSearch.get()
    if languageBookSearch.get() != "":
        dict['język'] = languageBookSearch.get()

    cena = {}
    if priceBookSearchOD.get() != "":
        cena['$gt'] = float(priceBookSearchOD.get())
    if priceBookSearchDO.get() != "":
        cena['$lt'] = float(priceBookSearchDO.get())
    if priceBookSearchDO.get() != "" or priceBookSearchOD.get() != "":
        dict['cena'] = cena
    pom = collectionBook.find(dict)