for best to take the e-mail-adress in this link, to find at "Zuständige Stelle":http://www.wien.gv.at/amtshelfer/kultur/archiv/forschung/his...
better then the online-formular in this way. ;)
as Floridsdorf became a community of Vienna on 10th Jan. 1905 they must be found in the files: http://en.wikipedia.org/wiki/Floridsdorf
i personally got answer always in some days or a week about e-mail and asked not only one time. ;) only one inquiry needed 3 months.